diff --git a/vendor/github.com/pmezard/go-difflib/LICENSE b/vendor/github.com/pmezard/go-difflib/LICENSE
new file mode 100644
index 0000000..c67dad6
--- /dev/null
+++ b/vendor/github.com/pmezard/go-difflib/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2013, Patrick Mezard
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+    The names of its contributors may not be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/pmezard/go-difflib/difflib/difflib.go b/vendor/github.com/pmezard/go-difflib/difflib/difflib.go
new file mode 100644
index 0000000..003e99f
--- /dev/null
+++ b/vendor/github.com/pmezard/go-difflib/difflib/difflib.go
@@ -0,0 +1,772 @@
+// Package difflib is a partial port of Python difflib module.
+//
+// It provides tools to compare sequences of strings and generate textual diffs.
+//
+// The following class and functions have been ported:
+//
+// - SequenceMatcher
+//
+// - unified_diff
+//
+// - context_diff
+//
+// Getting unified diffs was the main goal of the port. Keep in mind this code
+// is mostly suitable to output text differences in a human friendly way, there
+// are no guarantees generated diffs are consumable by patch(1).
+package difflib
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func calculateRatio(matches, length int) float64 {
+	if length > 0 {
+		return 2.0 * float64(matches) / float64(length)
+	}
+	return 1.0
+}
+
+type Match struct {
+	A    int
+	B    int
+	Size int
+}
+
+type OpCode struct {
+	Tag byte
+	I1  int
+	I2  int
+	J1  int
+	J2  int
+}
+
+// SequenceMatcher compares sequence of strings. The basic
+// algorithm predates, and is a little fancier than, an algorithm
+// published in the late 1980's by Ratcliff and Obershelp under the
+// hyperbolic name "gestalt pattern matching".  The basic idea is to find
+// the longest contiguous matching subsequence that contains no "junk"
+// elements (R-O doesn't address junk).  The same idea is then applied
+// recursively to the pieces of the sequences to the left and to the right
+// of the matching subsequence.  This does not yield minimal edit
+// sequences, but does tend to yield matches that "look right" to people.
+//
+// SequenceMatcher tries to compute a "human-friendly diff" between two
+// sequences.  Unlike e.g. UNIX(tm) diff, the fundamental notion is the
+// longest *contiguous* & junk-free matching subsequence.  That's what
+// catches peoples' eyes.  The Windows(tm) windiff has another interesting
+// notion, pairing up elements that appear uniquely in each sequence.
+// That, and the method here, appear to yield more intuitive difference
+// reports than does diff.  This method appears to be the least vulnerable
+// to synching up on blocks of "junk lines", though (like blank lines in
+// ordinary text files, or maybe "<P>" lines in HTML files).  That may be
+// because this is the only method of the 3 that has a *concept* of
+// "junk" <wink>.
+//
+// Timing:  Basic R-O is cubic time worst case and quadratic time expected
+// case.  SequenceMatcher is quadratic time for the worst case and has
+// expected-case behavior dependent in a complicated way on how many
+// elements the sequences have in common; best case time is linear.
+type SequenceMatcher struct {
+	a              []string
+	b              []string
+	b2j            map[string][]int
+	IsJunk         func(string) bool
+	autoJunk       bool
+	bJunk          map[string]struct{}
+	matchingBlocks []Match
+	fullBCount     map[string]int
+	bPopular       map[string]struct{}
+	opCodes        []OpCode
+}
+
+func NewMatcher(a, b []string) *SequenceMatcher {
+	m := SequenceMatcher{autoJunk: true}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+func NewMatcherWithJunk(a, b []string, autoJunk bool,
+	isJunk func(string) bool) *SequenceMatcher {
+
+	m := SequenceMatcher{IsJunk: isJunk, autoJunk: autoJunk}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+// Set two sequences to be compared.
+func (m *SequenceMatcher) SetSeqs(a, b []string) {
+	m.SetSeq1(a)
+	m.SetSeq2(b)
+}
+
+// Set the first sequence to be compared. The second sequence to be compared is
+// not changed.
+//
+// SequenceMatcher computes and caches detailed information about the second
+// sequence, so if you want to compare one sequence S against many sequences,
+// use .SetSeq2(s) once and call .SetSeq1(x) repeatedly for each of the other
+// sequences.
+//
+// See also SetSeqs() and SetSeq2().
+func (m *SequenceMatcher) SetSeq1(a []string) {
+	if &a == &m.a {
+		return
+	}
+	m.a = a
+	m.matchingBlocks = nil
+	m.opCodes = nil
+}
+
+// Set the second sequence to be compared. The first sequence to be compared is
+// not changed.
+func (m *SequenceMatcher) SetSeq2(b []string) {
+	if &b == &m.b {
+		return
+	}
+	m.b = b
+	m.matchingBlocks = nil
+	m.opCodes = nil
+	m.fullBCount = nil
+	m.chainB()
+}
+
+func (m *SequenceMatcher) chainB() {
+	// Populate line -> index mapping
+	b2j := map[string][]int{}
+	for i, s := range m.b {
+		indices := b2j[s]
+		indices = append(indices, i)
+		b2j[s] = indices
+	}
+
+	// Purge junk elements
+	m.bJunk = map[string]struct{}{}
+	if m.IsJunk != nil {
+		junk := m.bJunk
+		for s, _ := range b2j {
+			if m.IsJunk(s) {
+				junk[s] = struct{}{}
+			}
+		}
+		for s, _ := range junk {
+			delete(b2j, s)
+		}
+	}
+
+	// Purge remaining popular elements
+	popular := map[string]struct{}{}
+	n := len(m.b)
+	if m.autoJunk && n >= 200 {
+		ntest := n/100 + 1
+		for s, indices := range b2j {
+			if len(indices) > ntest {
+				popular[s] = struct{}{}
+			}
+		}
+		for s, _ := range popular {
+			delete(b2j, s)
+		}
+	}
+	m.bPopular = popular
+	m.b2j = b2j
+}
+
+func (m *SequenceMatcher) isBJunk(s string) bool {
+	_, ok := m.bJunk[s]
+	return ok
+}
+
+// Find longest matching block in a[alo:ahi] and b[blo:bhi].
+//
+// If IsJunk is not defined:
+//
+// Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
+//     alo <= i <= i+k <= ahi
+//     blo <= j <= j+k <= bhi
+// and for all (i',j',k') meeting those conditions,
+//     k >= k'
+//     i <= i'
+//     and if i == i', j <= j'
+//
+// In other words, of all maximal matching blocks, return one that
+// starts earliest in a, and of all those maximal matching blocks that
+// start earliest in a, return the one that starts earliest in b.
+//
+// If IsJunk is defined, first the longest matching block is
+// determined as above, but with the additional restriction that no
+// junk element appears in the block.  Then that block is extended as
+// far as possible by matching (only) junk elements on both sides.  So
+// the resulting block never matches on junk except as identical junk
+// happens to be adjacent to an "interesting" match.
+//
+// If no blocks match, return (alo, blo, 0).
+func (m *SequenceMatcher) findLongestMatch(alo, ahi, blo, bhi int) Match {
+	// CAUTION:  stripping common prefix or suffix would be incorrect.
+	// E.g.,
+	//    ab
+	//    acab
+	// Longest matching block is "ab", but if common prefix is
+	// stripped, it's "a" (tied with "b").  UNIX(tm) diff does so
+	// strip, so ends up claiming that ab is changed to acab by
+	// inserting "ca" in the middle.  That's minimal but unintuitive:
+	// "it's obvious" that someone inserted "ac" at the front.
+	// Windiff ends up at the same place as diff, but by pairing up
+	// the unique 'b's and then matching the first two 'a's.
+	besti, bestj, bestsize := alo, blo, 0
+
+	// find longest junk-free match
+	// during an iteration of the loop, j2len[j] = length of longest
+	// junk-free match ending with a[i-1] and b[j]
+	j2len := map[int]int{}
+	for i := alo; i != ahi; i++ {
+		// look at all instances of a[i] in b; note that because
+		// b2j has no junk keys, the loop is skipped if a[i] is junk
+		newj2len := map[int]int{}
+		for _, j := range m.b2j[m.a[i]] {
+			// a[i] matches b[j]
+			if j < blo {
+				continue
+			}
+			if j >= bhi {
+				break
+			}
+			k := j2len[j-1] + 1
+			newj2len[j] = k
+			if k > bestsize {
+				besti, bestj, bestsize = i-k+1, j-k+1, k
+			}
+		}
+		j2len = newj2len
+	}
+
+	// Extend the best by non-junk elements on each end.  In particular,
+	// "popular" non-junk elements aren't in b2j, which greatly speeds
+	// the inner loop above, but also means "the best" match so far
+	// doesn't contain any junk *or* popular non-junk elements.
+	for besti > alo && bestj > blo && !m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		!m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	// Now that we have a wholly interesting match (albeit possibly
+	// empty!), we may as well suck up the matching junk on each
+	// side of it too.  Can't think of a good reason not to, and it
+	// saves post-processing the (possibly considerable) expense of
+	// figuring out what to do with it.  In the case of an empty
+	// interesting match, this is clearly the right thing to do,
+	// because no other kind of match is possible in the regions.
+	for besti > alo && bestj > blo && m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	return Match{A: besti, B: bestj, Size: bestsize}
+}
+
+// Return list of triples describing matching subsequences.
+//
+// Each triple is of the form (i, j, n), and means that
+// a[i:i+n] == b[j:j+n].  The triples are monotonically increasing in
+// i and in j. It's also guaranteed that if (i, j, n) and (i', j', n') are
+// adjacent triples in the list, and the second is not the last triple in the
+// list, then i+n != i' or j+n != j'. IOW, adjacent triples never describe
+// adjacent equal blocks.
+//
+// The last triple is a dummy, (len(a), len(b), 0), and is the only
+// triple with n==0.
+func (m *SequenceMatcher) GetMatchingBlocks() []Match {
+	if m.matchingBlocks != nil {
+		return m.matchingBlocks
+	}
+
+	var matchBlocks func(alo, ahi, blo, bhi int, matched []Match) []Match
+	matchBlocks = func(alo, ahi, blo, bhi int, matched []Match) []Match {
+		match := m.findLongestMatch(alo, ahi, blo, bhi)
+		i, j, k := match.A, match.B, match.Size
+		if match.Size > 0 {
+			if alo < i && blo < j {
+				matched = matchBlocks(alo, i, blo, j, matched)
+			}
+			matched = append(matched, match)
+			if i+k < ahi && j+k < bhi {
+				matched = matchBlocks(i+k, ahi, j+k, bhi, matched)
+			}
+		}
+		return matched
+	}
+	matched := matchBlocks(0, len(m.a), 0, len(m.b), nil)
+
+	// It's possible that we have adjacent equal blocks in the
+	// matching_blocks list now.
+	nonAdjacent := []Match{}
+	i1, j1, k1 := 0, 0, 0
+	for _, b := range matched {
+		// Is this block adjacent to i1, j1, k1?
+		i2, j2, k2 := b.A, b.B, b.Size
+		if i1+k1 == i2 && j1+k1 == j2 {
+			// Yes, so collapse them -- this just increases the length of
+			// the first block by the length of the second, and the first
+			// block so lengthened remains the block to compare against.
+			k1 += k2
+		} else {
+			// Not adjacent.  Remember the first block (k1==0 means it's
+			// the dummy we started with), and make the second block the
+			// new block to compare against.
+			if k1 > 0 {
+				nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+			}
+			i1, j1, k1 = i2, j2, k2
+		}
+	}
+	if k1 > 0 {
+		nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+	}
+
+	nonAdjacent = append(nonAdjacent, Match{len(m.a), len(m.b), 0})
+	m.matchingBlocks = nonAdjacent
+	return m.matchingBlocks
+}
+
+// Return list of 5-tuples describing how to turn a into b.
+//
+// Each tuple is of the form (tag, i1, i2, j1, j2).  The first tuple
+// has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
+// tuple preceding it, and likewise for j1 == the previous j2.
+//
+// The tags are characters, with these meanings:
+//
+// 'r' (replace):  a[i1:i2] should be replaced by b[j1:j2]
+//
+// 'd' (delete):   a[i1:i2] should be deleted, j1==j2 in this case.
+//
+// 'i' (insert):   b[j1:j2] should be inserted at a[i1:i1], i1==i2 in this case.
+//
+// 'e' (equal):    a[i1:i2] == b[j1:j2]
+func (m *SequenceMatcher) GetOpCodes() []OpCode {
+	if m.opCodes != nil {
+		return m.opCodes
+	}
+	i, j := 0, 0
+	matching := m.GetMatchingBlocks()
+	opCodes := make([]OpCode, 0, len(matching))
+	for _, m := range matching {
+		//  invariant:  we've pumped out correct diffs to change
+		//  a[:i] into b[:j], and the next matching block is
+		//  a[ai:ai+size] == b[bj:bj+size]. So we need to pump
+		//  out a diff to change a[i:ai] into b[j:bj], pump out
+		//  the matching block, and move (i,j) beyond the match
+		ai, bj, size := m.A, m.B, m.Size
+		tag := byte(0)
+		if i < ai && j < bj {
+			tag = 'r'
+		} else if i < ai {
+			tag = 'd'
+		} else if j < bj {
+			tag = 'i'
+		}
+		if tag > 0 {
+			opCodes = append(opCodes, OpCode{tag, i, ai, j, bj})
+		}
+		i, j = ai+size, bj+size
+		// the list of matching blocks is terminated by a
+		// sentinel with size 0
+		if size > 0 {
+			opCodes = append(opCodes, OpCode{'e', ai, i, bj, j})
+		}
+	}
+	m.opCodes = opCodes
+	return m.opCodes
+}
+
+// Isolate change clusters by eliminating ranges with no changes.
+//
+// Return a generator of groups with up to n lines of context.
+// Each group is in the same format as returned by GetOpCodes().
+func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
+	if n < 0 {
+		n = 3
+	}
+	codes := m.GetOpCodes()
+	if len(codes) == 0 {
+		codes = []OpCode{OpCode{'e', 0, 1, 0, 1}}
+	}
+	// Fixup leading and trailing groups if they show no changes.
+	if codes[0].Tag == 'e' {
+		c := codes[0]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+	}
+	if codes[len(codes)-1].Tag == 'e' {
+		c := codes[len(codes)-1]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+	}
+	nn := n + n
+	groups := [][]OpCode{}
+	group := []OpCode{}
+	for _, c := range codes {
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		// End the current group and start a new one whenever
+		// there is a large range with no changes.
+		if c.Tag == 'e' && i2-i1 > nn {
+			group = append(group, OpCode{c.Tag, i1, min(i2, i1+n),
+				j1, min(j2, j1+n)})
+			groups = append(groups, group)
+			group = []OpCode{}
+			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+		}
+		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
+	}
+	if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
+		groups = append(groups, group)
+	}
+	return groups
+}
+
+// Return a measure of the sequences' similarity (float in [0,1]).
+//
+// Where T is the total number of elements in both sequences, and
+// M is the number of matches, this is 2.0*M / T.
+// Note that this is 1 if the sequences are identical, and 0 if
+// they have nothing in common.
+//
+// .Ratio() is expensive to compute if you haven't already computed
+// .GetMatchingBlocks() or .GetOpCodes(), in which case you may
+// want to try .QuickRatio() or .RealQuickRation() first to get an
+// upper bound.
+func (m *SequenceMatcher) Ratio() float64 {
+	matches := 0
+	for _, m := range m.GetMatchingBlocks() {
+		matches += m.Size
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() relatively quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute.
+func (m *SequenceMatcher) QuickRatio() float64 {
+	// viewing a and b as multisets, set matches to the cardinality
+	// of their intersection; this counts the number of matches
+	// without regard to order, so is clearly an upper bound
+	if m.fullBCount == nil {
+		m.fullBCount = map[string]int{}
+		for _, s := range m.b {
+			m.fullBCount[s] = m.fullBCount[s] + 1
+		}
+	}
+
+	// avail[x] is the number of times x appears in 'b' less the
+	// number of times we've seen it in 'a' so far ... kinda
+	avail := map[string]int{}
+	matches := 0
+	for _, s := range m.a {
+		n, ok := avail[s]
+		if !ok {
+			n = m.fullBCount[s]
+		}
+		avail[s] = n - 1
+		if n > 0 {
+			matches += 1
+		}
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() very quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute than either .Ratio() or .QuickRatio().
+func (m *SequenceMatcher) RealQuickRatio() float64 {
+	la, lb := len(m.a), len(m.b)
+	return calculateRatio(min(la, lb), la+lb)
+}
+
+// Convert range to the "ed" format
+func formatRangeUnified(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	if length == 0 {
+		beginning -= 1 // empty ranges begin at line just before the range
+	}
+	return fmt.Sprintf("%d,%d", beginning, length)
+}
+
+// Unified diff parameters
+type UnifiedDiff struct {
+	A        []string // First sequence lines
+	FromFile string   // First file name
+	FromDate string   // First file time
+	B        []string // Second sequence lines
+	ToFile   string   // Second file name
+	ToDate   string   // Second file time
+	Eol      string   // Headers end of line, defaults to LF
+	Context  int      // Number of context lines
+}
+
+// Compare two sequences of lines; generate the delta as a unified diff.
+//
+// Unified diffs are a compact way of showing line changes and a few
+// lines of context.  The number of context lines is set by 'n' which
+// defaults to three.
+//
+// By default, the diff control lines (those with ---, +++, or @@) are
+// created with a trailing newline.  This is helpful so that inputs
+// created from file.readlines() result in diffs that are suitable for
+// file.writelines() since both the inputs and outputs have trailing
+// newlines.
+//
+// For inputs that do not have trailing newlines, set the lineterm
+// argument to "" so that the output will be uniformly newline free.
+//
+// The unidiff format normally has a header for filenames and modification
+// times.  Any or all of these may be specified using strings for
+// 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
+// The modification times are normally expressed in the ISO 8601 format.
+func WriteUnifiedDiff(writer io.Writer, diff UnifiedDiff) error {
+	buf := bufio.NewWriter(writer)
+	defer buf.Flush()
+	wf := func(format string, args ...interface{}) error {
+		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		return err
+	}
+	ws := func(s string) error {
+		_, err := buf.WriteString(s)
+		return err
+	}
+
+	if len(diff.Eol) == 0 {
+		diff.Eol = "\n"
+	}
+
+	started := false
+	m := NewMatcher(diff.A, diff.B)
+	for _, g := range m.GetGroupedOpCodes(diff.Context) {
+		if !started {
+			started = true
+			fromDate := ""
+			if len(diff.FromDate) > 0 {
+				fromDate = "\t" + diff.FromDate
+			}
+			toDate := ""
+			if len(diff.ToDate) > 0 {
+				toDate = "\t" + diff.ToDate
+			}
+			if diff.FromFile != "" || diff.ToFile != "" {
+				err := wf("--- %s%s%s", diff.FromFile, fromDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+				err = wf("+++ %s%s%s", diff.ToFile, toDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+			}
+		}
+		first, last := g[0], g[len(g)-1]
+		range1 := formatRangeUnified(first.I1, last.I2)
+		range2 := formatRangeUnified(first.J1, last.J2)
+		if err := wf("@@ -%s +%s @@%s", range1, range2, diff.Eol); err != nil {
+			return err
+		}
+		for _, c := range g {
+			i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+			if c.Tag == 'e' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws(" " + line); err != nil {
+						return err
+					}
+				}
+				continue
+			}
+			if c.Tag == 'r' || c.Tag == 'd' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws("-" + line); err != nil {
+						return err
+					}
+				}
+			}
+			if c.Tag == 'r' || c.Tag == 'i' {
+				for _, line := range diff.B[j1:j2] {
+					if err := ws("+" + line); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// Like WriteUnifiedDiff but returns the diff a string.
+func GetUnifiedDiffString(diff UnifiedDiff) (string, error) {
+	w := &bytes.Buffer{}
+	err := WriteUnifiedDiff(w, diff)
+	return string(w.Bytes()), err
+}
+
+// Convert range to the "ed" format.
+func formatRangeContext(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 0 {
+		beginning -= 1 // empty ranges begin at line just before the range
+	}
+	if length <= 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	return fmt.Sprintf("%d,%d", beginning, beginning+length-1)
+}
+
+type ContextDiff UnifiedDiff
+
+// Compare two sequences of lines; generate the delta as a context diff.
+//
+// Context diffs are a compact way of showing line changes and a few
+// lines of context. The number of context lines is set by diff.Context
+// which defaults to three.
+//
+// By default, the diff control lines (those with *** or ---) are
+// created with a trailing newline.
+//
+// For inputs that do not have trailing newlines, set the diff.Eol
+// argument to "" so that the output will be uniformly newline free.
+//
+// The context diff format normally has a header for filenames and
+// modification times.  Any or all of these may be specified using
+// strings for diff.FromFile, diff.ToFile, diff.FromDate, diff.ToDate.
+// The modification times are normally expressed in the ISO 8601 format.
+// If not specified, the strings default to blanks.
+func WriteContextDiff(writer io.Writer, diff ContextDiff) error {
+	buf := bufio.NewWriter(writer)
+	defer buf.Flush()
+	var diffErr error
+	wf := func(format string, args ...interface{}) {
+		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		if diffErr == nil && err != nil {
+			diffErr = err
+		}
+	}
+	ws := func(s string) {
+		_, err := buf.WriteString(s)
+		if diffErr == nil && err != nil {
+			diffErr = err
+		}
+	}
+
+	if len(diff.Eol) == 0 {
+		diff.Eol = "\n"
+	}
+
+	prefix := map[byte]string{
+		'i': "+ ",
+		'd': "- ",
+		'r': "! ",
+		'e': "  ",
+	}
+
+	started := false
+	m := NewMatcher(diff.A, diff.B)
+	for _, g := range m.GetGroupedOpCodes(diff.Context) {
+		if !started {
+			started = true
+			fromDate := ""
+			if len(diff.FromDate) > 0 {
+				fromDate = "\t" + diff.FromDate
+			}
+			toDate := ""
+			if len(diff.ToDate) > 0 {
+				toDate = "\t" + diff.ToDate
+			}
+			if diff.FromFile != "" || diff.ToFile != "" {
+				wf("*** %s%s%s", diff.FromFile, fromDate, diff.Eol)
+				wf("--- %s%s%s", diff.ToFile, toDate, diff.Eol)
+			}
+		}
+
+		first, last := g[0], g[len(g)-1]
+		ws("***************" + diff.Eol)
+
+		range1 := formatRangeContext(first.I1, last.I2)
+		wf("*** %s ****%s", range1, diff.Eol)
+		for _, c := range g {
+			if c.Tag == 'r' || c.Tag == 'd' {
+				for _, cc := range g {
+					if cc.Tag == 'i' {
+						continue
+					}
+					for _, line := range diff.A[cc.I1:cc.I2] {
+						ws(prefix[cc.Tag] + line)
+					}
+				}
+				break
+			}
+		}
+
+		range2 := formatRangeContext(first.J1, last.J2)
+		wf("--- %s ----%s", range2, diff.Eol)
+		for _, c := range g {
+			if c.Tag == 'r' || c.Tag == 'i' {
+				for _, cc := range g {
+					if cc.Tag == 'd' {
+						continue
+					}
+					for _, line := range diff.B[cc.J1:cc.J2] {
+						ws(prefix[cc.Tag] + line)
+					}
+				}
+				break
+			}
+		}
+	}
+	return diffErr
+}
+
+// Like WriteContextDiff but returns the diff a string.
+func GetContextDiffString(diff ContextDiff) (string, error) {
+	w := &bytes.Buffer{}
+	err := WriteContextDiff(w, diff)
+	return string(w.Bytes()), err
+}
+
+// Split a string on "\n" while preserving them. The output can be used
+// as input for UnifiedDiff and ContextDiff structures.
+func SplitLines(s string) []string {
+	lines := strings.SplitAfter(s, "\n")
+	lines[len(lines)-1] += "\n"
+	return lines
+}
diff --git a/vendor/github.com/stretchr/testify/LICENSE b/vendor/github.com/stretchr/testify/LICENSE
new file mode 100644
index 0000000..f38ec59
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2012-2018 Mat Ryer and Tyler Bunnell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/stretchr/testify/assert/assertion_format.go b/vendor/github.com/stretchr/testify/assert/assertion_format.go
new file mode 100644
index 0000000..e0364e9
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertion_format.go
@@ -0,0 +1,566 @@
+/*
+* CODE GENERATED AUTOMATICALLY WITH github.com/stretchr/testify/_codegen
+* THIS FILE MUST NOT BE EDITED BY HAND
+ */
+
+package assert
+
+import (
+	http "net/http"
+	url "net/url"
+	time "time"
+)
+
+// Conditionf uses a Comparison to assert a complex condition.
+func Conditionf(t TestingT, comp Comparison, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Condition(t, comp, append([]interface{}{msg}, args...)...)
+}
+
+// Containsf asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    assert.Containsf(t, "Hello World", "World", "error message %s", "formatted")
+//    assert.Containsf(t, ["Hello", "World"], "World", "error message %s", "formatted")
+//    assert.Containsf(t, {"Hello": "World"}, "Hello", "error message %s", "formatted")
+func Containsf(t TestingT, s interface{}, contains interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Contains(t, s, contains, append([]interface{}{msg}, args...)...)
+}
+
+// DirExistsf checks whether a directory exists in the given path. It also fails if the path is a file rather a directory or there is an error checking whether it exists.
+func DirExistsf(t TestingT, path string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return DirExists(t, path, append([]interface{}{msg}, args...)...)
+}
+
+// ElementsMatchf asserts that the specified listA(array, slice...) is equal to specified
+// listB(array, slice...) ignoring the order of the elements. If there are duplicate elements,
+// the number of appearances of each of them in both lists should match.
+//
+// assert.ElementsMatchf(t, [1, 3, 2, 3], [1, 3, 3, 2], "error message %s", "formatted")
+func ElementsMatchf(t TestingT, listA interface{}, listB interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return ElementsMatch(t, listA, listB, append([]interface{}{msg}, args...)...)
+}
+
+// Emptyf asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  assert.Emptyf(t, obj, "error message %s", "formatted")
+func Emptyf(t TestingT, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Empty(t, object, append([]interface{}{msg}, args...)...)
+}
+
+// Equalf asserts that two objects are equal.
+//
+//    assert.Equalf(t, 123, 123, "error message %s", "formatted")
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses). Function equality
+// cannot be determined and will always fail.
+func Equalf(t TestingT, expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Equal(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// EqualErrorf asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   assert.EqualErrorf(t, err,  expectedErrorString, "error message %s", "formatted")
+func EqualErrorf(t TestingT, theError error, errString string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualError(t, theError, errString, append([]interface{}{msg}, args...)...)
+}
+
+// EqualValuesf asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    assert.EqualValuesf(t, uint32(123, "error message %s", "formatted"), int32(123))
+func EqualValuesf(t TestingT, expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualValues(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// Errorf asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.Errorf(t, err, "error message %s", "formatted") {
+// 	   assert.Equal(t, expectedErrorf, err)
+//   }
+func Errorf(t TestingT, err error, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Error(t, err, append([]interface{}{msg}, args...)...)
+}
+
+// Eventuallyf asserts that given condition will be met in waitFor time,
+// periodically checking target function each tick.
+//
+//    assert.Eventuallyf(t, func() bool { return true; }, time.Second, 10*time.Millisecond, "error message %s", "formatted")
+func Eventuallyf(t TestingT, condition func() bool, waitFor time.Duration, tick time.Duration, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Eventually(t, condition, waitFor, tick, append([]interface{}{msg}, args...)...)
+}
+
+// Exactlyf asserts that two objects are equal in value and type.
+//
+//    assert.Exactlyf(t, int32(123, "error message %s", "formatted"), int64(123))
+func Exactlyf(t TestingT, expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Exactly(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// Failf reports a failure through
+func Failf(t TestingT, failureMessage string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Fail(t, failureMessage, append([]interface{}{msg}, args...)...)
+}
+
+// FailNowf fails test
+func FailNowf(t TestingT, failureMessage string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return FailNow(t, failureMessage, append([]interface{}{msg}, args...)...)
+}
+
+// Falsef asserts that the specified value is false.
+//
+//    assert.Falsef(t, myBool, "error message %s", "formatted")
+func Falsef(t TestingT, value bool, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return False(t, value, append([]interface{}{msg}, args...)...)
+}
+
+// FileExistsf checks whether a file exists in the given path. It also fails if the path points to a directory or there is an error when trying to check the file.
+func FileExistsf(t TestingT, path string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return FileExists(t, path, append([]interface{}{msg}, args...)...)
+}
+
+// Greaterf asserts that the first element is greater than the second
+//
+//    assert.Greaterf(t, 2, 1, "error message %s", "formatted")
+//    assert.Greaterf(t, float64(2, "error message %s", "formatted"), float64(1))
+//    assert.Greaterf(t, "b", "a", "error message %s", "formatted")
+func Greaterf(t TestingT, e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Greater(t, e1, e2, append([]interface{}{msg}, args...)...)
+}
+
+// GreaterOrEqualf asserts that the first element is greater than or equal to the second
+//
+//    assert.GreaterOrEqualf(t, 2, 1, "error message %s", "formatted")
+//    assert.GreaterOrEqualf(t, 2, 2, "error message %s", "formatted")
+//    assert.GreaterOrEqualf(t, "b", "a", "error message %s", "formatted")
+//    assert.GreaterOrEqualf(t, "b", "b", "error message %s", "formatted")
+func GreaterOrEqualf(t TestingT, e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return GreaterOrEqual(t, e1, e2, append([]interface{}{msg}, args...)...)
+}
+
+// HTTPBodyContainsf asserts that a specified handler returns a
+// body that contains a string.
+//
+//  assert.HTTPBodyContainsf(t, myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky", "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyContainsf(t TestingT, handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyContains(t, handler, method, url, values, str, append([]interface{}{msg}, args...)...)
+}
+
+// HTTPBodyNotContainsf asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  assert.HTTPBodyNotContainsf(t, myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky", "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyNotContainsf(t TestingT, handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyNotContains(t, handler, method, url, values, str, append([]interface{}{msg}, args...)...)
+}
+
+// HTTPErrorf asserts that a specified handler returns an error status code.
+//
+//  assert.HTTPErrorf(t, myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true, "error message %s", "formatted") or not (false).
+func HTTPErrorf(t TestingT, handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPError(t, handler, method, url, values, append([]interface{}{msg}, args...)...)
+}
+
+// HTTPRedirectf asserts that a specified handler returns a redirect status code.
+//
+//  assert.HTTPRedirectf(t, myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true, "error message %s", "formatted") or not (false).
+func HTTPRedirectf(t TestingT, handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPRedirect(t, handler, method, url, values, append([]interface{}{msg}, args...)...)
+}
+
+// HTTPSuccessf asserts that a specified handler returns a success status code.
+//
+//  assert.HTTPSuccessf(t, myHandler, "POST", "http://www.google.com", nil, "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPSuccessf(t TestingT, handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPSuccess(t, handler, method, url, values, append([]interface{}{msg}, args...)...)
+}
+
+// Implementsf asserts that an object is implemented by the specified interface.
+//
+//    assert.Implementsf(t, (*MyInterface, "error message %s", "formatted")(nil), new(MyObject))
+func Implementsf(t TestingT, interfaceObject interface{}, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Implements(t, interfaceObject, object, append([]interface{}{msg}, args...)...)
+}
+
+// InDeltaf asserts that the two numerals are within delta of each other.
+//
+// 	 assert.InDeltaf(t, math.Pi, (22 / 7.0, "error message %s", "formatted"), 0.01)
+func InDeltaf(t TestingT, expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDelta(t, expected, actual, delta, append([]interface{}{msg}, args...)...)
+}
+
+// InDeltaMapValuesf is the same as InDelta, but it compares all values between two maps. Both maps must have exactly the same keys.
+func InDeltaMapValuesf(t TestingT, expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaMapValues(t, expected, actual, delta, append([]interface{}{msg}, args...)...)
+}
+
+// InDeltaSlicef is the same as InDelta, except it compares two slices.
+func InDeltaSlicef(t TestingT, expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaSlice(t, expected, actual, delta, append([]interface{}{msg}, args...)...)
+}
+
+// InEpsilonf asserts that expected and actual have a relative error less than epsilon
+func InEpsilonf(t TestingT, expected interface{}, actual interface{}, epsilon float64, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilon(t, expected, actual, epsilon, append([]interface{}{msg}, args...)...)
+}
+
+// InEpsilonSlicef is the same as InEpsilon, except it compares each value from two slices.
+func InEpsilonSlicef(t TestingT, expected interface{}, actual interface{}, epsilon float64, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilonSlice(t, expected, actual, epsilon, append([]interface{}{msg}, args...)...)
+}
+
+// IsTypef asserts that the specified objects are of the same type.
+func IsTypef(t TestingT, expectedType interface{}, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return IsType(t, expectedType, object, append([]interface{}{msg}, args...)...)
+}
+
+// JSONEqf asserts that two JSON strings are equivalent.
+//
+//  assert.JSONEqf(t, `{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`, "error message %s", "formatted")
+func JSONEqf(t TestingT, expected string, actual string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return JSONEq(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// YAMLEqf asserts that two YAML strings are equivalent.
+func YAMLEqf(t TestingT, expected string, actual string, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return YAMLEq(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// Lenf asserts that the specified object has specific length.
+// Lenf also fails if the object has a type that len() not accept.
+//
+//    assert.Lenf(t, mySlice, 3, "error message %s", "formatted")
+func Lenf(t TestingT, object interface{}, length int, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Len(t, object, length, append([]interface{}{msg}, args...)...)
+}
+
+// Lessf asserts that the first element is less than the second
+//
+//    assert.Lessf(t, 1, 2, "error message %s", "formatted")
+//    assert.Lessf(t, float64(1, "error message %s", "formatted"), float64(2))
+//    assert.Lessf(t, "a", "b", "error message %s", "formatted")
+func Lessf(t TestingT, e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Less(t, e1, e2, append([]interface{}{msg}, args...)...)
+}
+
+// LessOrEqualf asserts that the first element is less than or equal to the second
+//
+//    assert.LessOrEqualf(t, 1, 2, "error message %s", "formatted")
+//    assert.LessOrEqualf(t, 2, 2, "error message %s", "formatted")
+//    assert.LessOrEqualf(t, "a", "b", "error message %s", "formatted")
+//    assert.LessOrEqualf(t, "b", "b", "error message %s", "formatted")
+func LessOrEqualf(t TestingT, e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return LessOrEqual(t, e1, e2, append([]interface{}{msg}, args...)...)
+}
+
+// Nilf asserts that the specified object is nil.
+//
+//    assert.Nilf(t, err, "error message %s", "formatted")
+func Nilf(t TestingT, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Nil(t, object, append([]interface{}{msg}, args...)...)
+}
+
+// NoErrorf asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.NoErrorf(t, err, "error message %s", "formatted") {
+// 	   assert.Equal(t, expectedObj, actualObj)
+//   }
+func NoErrorf(t TestingT, err error, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NoError(t, err, append([]interface{}{msg}, args...)...)
+}
+
+// NotContainsf asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    assert.NotContainsf(t, "Hello World", "Earth", "error message %s", "formatted")
+//    assert.NotContainsf(t, ["Hello", "World"], "Earth", "error message %s", "formatted")
+//    assert.NotContainsf(t, {"Hello": "World"}, "Earth", "error message %s", "formatted")
+func NotContainsf(t TestingT, s interface{}, contains interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotContains(t, s, contains, append([]interface{}{msg}, args...)...)
+}
+
+// NotEmptyf asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if assert.NotEmptyf(t, obj, "error message %s", "formatted") {
+//    assert.Equal(t, "two", obj[1])
+//  }
+func NotEmptyf(t TestingT, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEmpty(t, object, append([]interface{}{msg}, args...)...)
+}
+
+// NotEqualf asserts that the specified values are NOT equal.
+//
+//    assert.NotEqualf(t, obj1, obj2, "error message %s", "formatted")
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func NotEqualf(t TestingT, expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEqual(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// NotNilf asserts that the specified object is not nil.
+//
+//    assert.NotNilf(t, err, "error message %s", "formatted")
+func NotNilf(t TestingT, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotNil(t, object, append([]interface{}{msg}, args...)...)
+}
+
+// NotPanicsf asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   assert.NotPanicsf(t, func(){ RemainCalm() }, "error message %s", "formatted")
+func NotPanicsf(t TestingT, f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotPanics(t, f, append([]interface{}{msg}, args...)...)
+}
+
+// NotRegexpf asserts that a specified regexp does not match a string.
+//
+//  assert.NotRegexpf(t, regexp.MustCompile("starts", "error message %s", "formatted"), "it's starting")
+//  assert.NotRegexpf(t, "^start", "it's not starting", "error message %s", "formatted")
+func NotRegexpf(t TestingT, rx interface{}, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotRegexp(t, rx, str, append([]interface{}{msg}, args...)...)
+}
+
+// NotSubsetf asserts that the specified list(array, slice...) contains not all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.NotSubsetf(t, [1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]", "error message %s", "formatted")
+func NotSubsetf(t TestingT, list interface{}, subset interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotSubset(t, list, subset, append([]interface{}{msg}, args...)...)
+}
+
+// NotZerof asserts that i is not the zero value for its type.
+func NotZerof(t TestingT, i interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotZero(t, i, append([]interface{}{msg}, args...)...)
+}
+
+// Panicsf asserts that the code inside the specified PanicTestFunc panics.
+//
+//   assert.Panicsf(t, func(){ GoCrazy() }, "error message %s", "formatted")
+func Panicsf(t TestingT, f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Panics(t, f, append([]interface{}{msg}, args...)...)
+}
+
+// PanicsWithValuef asserts that the code inside the specified PanicTestFunc panics, and that
+// the recovered panic value equals the expected panic value.
+//
+//   assert.PanicsWithValuef(t, "crazy error", func(){ GoCrazy() }, "error message %s", "formatted")
+func PanicsWithValuef(t TestingT, expected interface{}, f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return PanicsWithValue(t, expected, f, append([]interface{}{msg}, args...)...)
+}
+
+// Regexpf asserts that a specified regexp matches a string.
+//
+//  assert.Regexpf(t, regexp.MustCompile("start", "error message %s", "formatted"), "it's starting")
+//  assert.Regexpf(t, "start...$", "it's not starting", "error message %s", "formatted")
+func Regexpf(t TestingT, rx interface{}, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Regexp(t, rx, str, append([]interface{}{msg}, args...)...)
+}
+
+// Samef asserts that two pointers reference the same object.
+//
+//    assert.Samef(t, ptr1, ptr2, "error message %s", "formatted")
+//
+// Both arguments must be pointer variables. Pointer variable sameness is
+// determined based on the equality of both type and value.
+func Samef(t TestingT, expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Same(t, expected, actual, append([]interface{}{msg}, args...)...)
+}
+
+// Subsetf asserts that the specified list(array, slice...) contains all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.Subsetf(t, [1, 2, 3], [1, 2], "But [1, 2, 3] does contain [1, 2]", "error message %s", "formatted")
+func Subsetf(t TestingT, list interface{}, subset interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Subset(t, list, subset, append([]interface{}{msg}, args...)...)
+}
+
+// Truef asserts that the specified value is true.
+//
+//    assert.Truef(t, myBool, "error message %s", "formatted")
+func Truef(t TestingT, value bool, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return True(t, value, append([]interface{}{msg}, args...)...)
+}
+
+// WithinDurationf asserts that the two times are within duration delta of each other.
+//
+//   assert.WithinDurationf(t, time.Now(), time.Now(), 10*time.Second, "error message %s", "formatted")
+func WithinDurationf(t TestingT, expected time.Time, actual time.Time, delta time.Duration, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return WithinDuration(t, expected, actual, delta, append([]interface{}{msg}, args...)...)
+}
+
+// Zerof asserts that i is the zero value for its type.
+func Zerof(t TestingT, i interface{}, msg string, args ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	return Zero(t, i, append([]interface{}{msg}, args...)...)
+}
diff --git a/vendor/github.com/stretchr/testify/assert/assertion_format.go.tmpl b/vendor/github.com/stretchr/testify/assert/assertion_format.go.tmpl
new file mode 100644
index 0000000..d2bb0b8
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertion_format.go.tmpl
@@ -0,0 +1,5 @@
+{{.CommentFormat}}
+func {{.DocInfo.Name}}f(t TestingT, {{.ParamsFormat}}) bool {
+	if h, ok := t.(tHelper); ok { h.Helper() }
+	return {{.DocInfo.Name}}(t, {{.ForwardedParamsFormat}})
+}
diff --git a/vendor/github.com/stretchr/testify/assert/assertion_forward.go b/vendor/github.com/stretchr/testify/assert/assertion_forward.go
new file mode 100644
index 0000000..2683040
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertion_forward.go
@@ -0,0 +1,1120 @@
+/*
+* CODE GENERATED AUTOMATICALLY WITH github.com/stretchr/testify/_codegen
+* THIS FILE MUST NOT BE EDITED BY HAND
+ */
+
+package assert
+
+import (
+	http "net/http"
+	url "net/url"
+	time "time"
+)
+
+// Condition uses a Comparison to assert a complex condition.
+func (a *Assertions) Condition(comp Comparison, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Condition(a.t, comp, msgAndArgs...)
+}
+
+// Conditionf uses a Comparison to assert a complex condition.
+func (a *Assertions) Conditionf(comp Comparison, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Conditionf(a.t, comp, msg, args...)
+}
+
+// Contains asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    a.Contains("Hello World", "World")
+//    a.Contains(["Hello", "World"], "World")
+//    a.Contains({"Hello": "World"}, "Hello")
+func (a *Assertions) Contains(s interface{}, contains interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Contains(a.t, s, contains, msgAndArgs...)
+}
+
+// Containsf asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    a.Containsf("Hello World", "World", "error message %s", "formatted")
+//    a.Containsf(["Hello", "World"], "World", "error message %s", "formatted")
+//    a.Containsf({"Hello": "World"}, "Hello", "error message %s", "formatted")
+func (a *Assertions) Containsf(s interface{}, contains interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Containsf(a.t, s, contains, msg, args...)
+}
+
+// DirExists checks whether a directory exists in the given path. It also fails if the path is a file rather a directory or there is an error checking whether it exists.
+func (a *Assertions) DirExists(path string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return DirExists(a.t, path, msgAndArgs...)
+}
+
+// DirExistsf checks whether a directory exists in the given path. It also fails if the path is a file rather a directory or there is an error checking whether it exists.
+func (a *Assertions) DirExistsf(path string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return DirExistsf(a.t, path, msg, args...)
+}
+
+// ElementsMatch asserts that the specified listA(array, slice...) is equal to specified
+// listB(array, slice...) ignoring the order of the elements. If there are duplicate elements,
+// the number of appearances of each of them in both lists should match.
+//
+// a.ElementsMatch([1, 3, 2, 3], [1, 3, 3, 2])
+func (a *Assertions) ElementsMatch(listA interface{}, listB interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return ElementsMatch(a.t, listA, listB, msgAndArgs...)
+}
+
+// ElementsMatchf asserts that the specified listA(array, slice...) is equal to specified
+// listB(array, slice...) ignoring the order of the elements. If there are duplicate elements,
+// the number of appearances of each of them in both lists should match.
+//
+// a.ElementsMatchf([1, 3, 2, 3], [1, 3, 3, 2], "error message %s", "formatted")
+func (a *Assertions) ElementsMatchf(listA interface{}, listB interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return ElementsMatchf(a.t, listA, listB, msg, args...)
+}
+
+// Empty asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  a.Empty(obj)
+func (a *Assertions) Empty(object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Empty(a.t, object, msgAndArgs...)
+}
+
+// Emptyf asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  a.Emptyf(obj, "error message %s", "formatted")
+func (a *Assertions) Emptyf(object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Emptyf(a.t, object, msg, args...)
+}
+
+// Equal asserts that two objects are equal.
+//
+//    a.Equal(123, 123)
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses). Function equality
+// cannot be determined and will always fail.
+func (a *Assertions) Equal(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Equal(a.t, expected, actual, msgAndArgs...)
+}
+
+// EqualError asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   a.EqualError(err,  expectedErrorString)
+func (a *Assertions) EqualError(theError error, errString string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualError(a.t, theError, errString, msgAndArgs...)
+}
+
+// EqualErrorf asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   a.EqualErrorf(err,  expectedErrorString, "error message %s", "formatted")
+func (a *Assertions) EqualErrorf(theError error, errString string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualErrorf(a.t, theError, errString, msg, args...)
+}
+
+// EqualValues asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    a.EqualValues(uint32(123), int32(123))
+func (a *Assertions) EqualValues(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualValues(a.t, expected, actual, msgAndArgs...)
+}
+
+// EqualValuesf asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    a.EqualValuesf(uint32(123, "error message %s", "formatted"), int32(123))
+func (a *Assertions) EqualValuesf(expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return EqualValuesf(a.t, expected, actual, msg, args...)
+}
+
+// Equalf asserts that two objects are equal.
+//
+//    a.Equalf(123, 123, "error message %s", "formatted")
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses). Function equality
+// cannot be determined and will always fail.
+func (a *Assertions) Equalf(expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Equalf(a.t, expected, actual, msg, args...)
+}
+
+// Error asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.Error(err) {
+// 	   assert.Equal(t, expectedError, err)
+//   }
+func (a *Assertions) Error(err error, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Error(a.t, err, msgAndArgs...)
+}
+
+// Errorf asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.Errorf(err, "error message %s", "formatted") {
+// 	   assert.Equal(t, expectedErrorf, err)
+//   }
+func (a *Assertions) Errorf(err error, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Errorf(a.t, err, msg, args...)
+}
+
+// Eventually asserts that given condition will be met in waitFor time,
+// periodically checking target function each tick.
+//
+//    a.Eventually(func() bool { return true; }, time.Second, 10*time.Millisecond)
+func (a *Assertions) Eventually(condition func() bool, waitFor time.Duration, tick time.Duration, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Eventually(a.t, condition, waitFor, tick, msgAndArgs...)
+}
+
+// Eventuallyf asserts that given condition will be met in waitFor time,
+// periodically checking target function each tick.
+//
+//    a.Eventuallyf(func() bool { return true; }, time.Second, 10*time.Millisecond, "error message %s", "formatted")
+func (a *Assertions) Eventuallyf(condition func() bool, waitFor time.Duration, tick time.Duration, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Eventuallyf(a.t, condition, waitFor, tick, msg, args...)
+}
+
+// Exactly asserts that two objects are equal in value and type.
+//
+//    a.Exactly(int32(123), int64(123))
+func (a *Assertions) Exactly(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Exactly(a.t, expected, actual, msgAndArgs...)
+}
+
+// Exactlyf asserts that two objects are equal in value and type.
+//
+//    a.Exactlyf(int32(123, "error message %s", "formatted"), int64(123))
+func (a *Assertions) Exactlyf(expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Exactlyf(a.t, expected, actual, msg, args...)
+}
+
+// Fail reports a failure through
+func (a *Assertions) Fail(failureMessage string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Fail(a.t, failureMessage, msgAndArgs...)
+}
+
+// FailNow fails test
+func (a *Assertions) FailNow(failureMessage string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return FailNow(a.t, failureMessage, msgAndArgs...)
+}
+
+// FailNowf fails test
+func (a *Assertions) FailNowf(failureMessage string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return FailNowf(a.t, failureMessage, msg, args...)
+}
+
+// Failf reports a failure through
+func (a *Assertions) Failf(failureMessage string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Failf(a.t, failureMessage, msg, args...)
+}
+
+// False asserts that the specified value is false.
+//
+//    a.False(myBool)
+func (a *Assertions) False(value bool, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return False(a.t, value, msgAndArgs...)
+}
+
+// Falsef asserts that the specified value is false.
+//
+//    a.Falsef(myBool, "error message %s", "formatted")
+func (a *Assertions) Falsef(value bool, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Falsef(a.t, value, msg, args...)
+}
+
+// FileExists checks whether a file exists in the given path. It also fails if the path points to a directory or there is an error when trying to check the file.
+func (a *Assertions) FileExists(path string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return FileExists(a.t, path, msgAndArgs...)
+}
+
+// FileExistsf checks whether a file exists in the given path. It also fails if the path points to a directory or there is an error when trying to check the file.
+func (a *Assertions) FileExistsf(path string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return FileExistsf(a.t, path, msg, args...)
+}
+
+// Greater asserts that the first element is greater than the second
+//
+//    a.Greater(2, 1)
+//    a.Greater(float64(2), float64(1))
+//    a.Greater("b", "a")
+func (a *Assertions) Greater(e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Greater(a.t, e1, e2, msgAndArgs...)
+}
+
+// GreaterOrEqual asserts that the first element is greater than or equal to the second
+//
+//    a.GreaterOrEqual(2, 1)
+//    a.GreaterOrEqual(2, 2)
+//    a.GreaterOrEqual("b", "a")
+//    a.GreaterOrEqual("b", "b")
+func (a *Assertions) GreaterOrEqual(e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return GreaterOrEqual(a.t, e1, e2, msgAndArgs...)
+}
+
+// GreaterOrEqualf asserts that the first element is greater than or equal to the second
+//
+//    a.GreaterOrEqualf(2, 1, "error message %s", "formatted")
+//    a.GreaterOrEqualf(2, 2, "error message %s", "formatted")
+//    a.GreaterOrEqualf("b", "a", "error message %s", "formatted")
+//    a.GreaterOrEqualf("b", "b", "error message %s", "formatted")
+func (a *Assertions) GreaterOrEqualf(e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return GreaterOrEqualf(a.t, e1, e2, msg, args...)
+}
+
+// Greaterf asserts that the first element is greater than the second
+//
+//    a.Greaterf(2, 1, "error message %s", "formatted")
+//    a.Greaterf(float64(2, "error message %s", "formatted"), float64(1))
+//    a.Greaterf("b", "a", "error message %s", "formatted")
+func (a *Assertions) Greaterf(e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Greaterf(a.t, e1, e2, msg, args...)
+}
+
+// HTTPBodyContains asserts that a specified handler returns a
+// body that contains a string.
+//
+//  a.HTTPBodyContains(myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyContains(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyContains(a.t, handler, method, url, values, str, msgAndArgs...)
+}
+
+// HTTPBodyContainsf asserts that a specified handler returns a
+// body that contains a string.
+//
+//  a.HTTPBodyContainsf(myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky", "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyContainsf(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyContainsf(a.t, handler, method, url, values, str, msg, args...)
+}
+
+// HTTPBodyNotContains asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  a.HTTPBodyNotContains(myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyNotContains(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyNotContains(a.t, handler, method, url, values, str, msgAndArgs...)
+}
+
+// HTTPBodyNotContainsf asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  a.HTTPBodyNotContainsf(myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky", "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyNotContainsf(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPBodyNotContainsf(a.t, handler, method, url, values, str, msg, args...)
+}
+
+// HTTPError asserts that a specified handler returns an error status code.
+//
+//  a.HTTPError(myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPError(handler http.HandlerFunc, method string, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPError(a.t, handler, method, url, values, msgAndArgs...)
+}
+
+// HTTPErrorf asserts that a specified handler returns an error status code.
+//
+//  a.HTTPErrorf(myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true, "error message %s", "formatted") or not (false).
+func (a *Assertions) HTTPErrorf(handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPErrorf(a.t, handler, method, url, values, msg, args...)
+}
+
+// HTTPRedirect asserts that a specified handler returns a redirect status code.
+//
+//  a.HTTPRedirect(myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPRedirect(handler http.HandlerFunc, method string, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPRedirect(a.t, handler, method, url, values, msgAndArgs...)
+}
+
+// HTTPRedirectf asserts that a specified handler returns a redirect status code.
+//
+//  a.HTTPRedirectf(myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true, "error message %s", "formatted") or not (false).
+func (a *Assertions) HTTPRedirectf(handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPRedirectf(a.t, handler, method, url, values, msg, args...)
+}
+
+// HTTPSuccess asserts that a specified handler returns a success status code.
+//
+//  a.HTTPSuccess(myHandler, "POST", "http://www.google.com", nil)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPSuccess(handler http.HandlerFunc, method string, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPSuccess(a.t, handler, method, url, values, msgAndArgs...)
+}
+
+// HTTPSuccessf asserts that a specified handler returns a success status code.
+//
+//  a.HTTPSuccessf(myHandler, "POST", "http://www.google.com", nil, "error message %s", "formatted")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPSuccessf(handler http.HandlerFunc, method string, url string, values url.Values, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return HTTPSuccessf(a.t, handler, method, url, values, msg, args...)
+}
+
+// Implements asserts that an object is implemented by the specified interface.
+//
+//    a.Implements((*MyInterface)(nil), new(MyObject))
+func (a *Assertions) Implements(interfaceObject interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Implements(a.t, interfaceObject, object, msgAndArgs...)
+}
+
+// Implementsf asserts that an object is implemented by the specified interface.
+//
+//    a.Implementsf((*MyInterface, "error message %s", "formatted")(nil), new(MyObject))
+func (a *Assertions) Implementsf(interfaceObject interface{}, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Implementsf(a.t, interfaceObject, object, msg, args...)
+}
+
+// InDelta asserts that the two numerals are within delta of each other.
+//
+// 	 a.InDelta(math.Pi, (22 / 7.0), 0.01)
+func (a *Assertions) InDelta(expected interface{}, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDelta(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// InDeltaMapValues is the same as InDelta, but it compares all values between two maps. Both maps must have exactly the same keys.
+func (a *Assertions) InDeltaMapValues(expected interface{}, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaMapValues(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// InDeltaMapValuesf is the same as InDelta, but it compares all values between two maps. Both maps must have exactly the same keys.
+func (a *Assertions) InDeltaMapValuesf(expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaMapValuesf(a.t, expected, actual, delta, msg, args...)
+}
+
+// InDeltaSlice is the same as InDelta, except it compares two slices.
+func (a *Assertions) InDeltaSlice(expected interface{}, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaSlice(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// InDeltaSlicef is the same as InDelta, except it compares two slices.
+func (a *Assertions) InDeltaSlicef(expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaSlicef(a.t, expected, actual, delta, msg, args...)
+}
+
+// InDeltaf asserts that the two numerals are within delta of each other.
+//
+// 	 a.InDeltaf(math.Pi, (22 / 7.0, "error message %s", "formatted"), 0.01)
+func (a *Assertions) InDeltaf(expected interface{}, actual interface{}, delta float64, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InDeltaf(a.t, expected, actual, delta, msg, args...)
+}
+
+// InEpsilon asserts that expected and actual have a relative error less than epsilon
+func (a *Assertions) InEpsilon(expected interface{}, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilon(a.t, expected, actual, epsilon, msgAndArgs...)
+}
+
+// InEpsilonSlice is the same as InEpsilon, except it compares each value from two slices.
+func (a *Assertions) InEpsilonSlice(expected interface{}, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilonSlice(a.t, expected, actual, epsilon, msgAndArgs...)
+}
+
+// InEpsilonSlicef is the same as InEpsilon, except it compares each value from two slices.
+func (a *Assertions) InEpsilonSlicef(expected interface{}, actual interface{}, epsilon float64, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilonSlicef(a.t, expected, actual, epsilon, msg, args...)
+}
+
+// InEpsilonf asserts that expected and actual have a relative error less than epsilon
+func (a *Assertions) InEpsilonf(expected interface{}, actual interface{}, epsilon float64, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return InEpsilonf(a.t, expected, actual, epsilon, msg, args...)
+}
+
+// IsType asserts that the specified objects are of the same type.
+func (a *Assertions) IsType(expectedType interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return IsType(a.t, expectedType, object, msgAndArgs...)
+}
+
+// IsTypef asserts that the specified objects are of the same type.
+func (a *Assertions) IsTypef(expectedType interface{}, object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return IsTypef(a.t, expectedType, object, msg, args...)
+}
+
+// JSONEq asserts that two JSON strings are equivalent.
+//
+//  a.JSONEq(`{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`)
+func (a *Assertions) JSONEq(expected string, actual string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return JSONEq(a.t, expected, actual, msgAndArgs...)
+}
+
+// JSONEqf asserts that two JSON strings are equivalent.
+//
+//  a.JSONEqf(`{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`, "error message %s", "formatted")
+func (a *Assertions) JSONEqf(expected string, actual string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return JSONEqf(a.t, expected, actual, msg, args...)
+}
+
+// YAMLEq asserts that two YAML strings are equivalent.
+func (a *Assertions) YAMLEq(expected string, actual string, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return YAMLEq(a.t, expected, actual, msgAndArgs...)
+}
+
+// YAMLEqf asserts that two YAML strings are equivalent.
+func (a *Assertions) YAMLEqf(expected string, actual string, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return YAMLEqf(a.t, expected, actual, msg, args...)
+}
+
+// Len asserts that the specified object has specific length.
+// Len also fails if the object has a type that len() not accept.
+//
+//    a.Len(mySlice, 3)
+func (a *Assertions) Len(object interface{}, length int, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Len(a.t, object, length, msgAndArgs...)
+}
+
+// Lenf asserts that the specified object has specific length.
+// Lenf also fails if the object has a type that len() not accept.
+//
+//    a.Lenf(mySlice, 3, "error message %s", "formatted")
+func (a *Assertions) Lenf(object interface{}, length int, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Lenf(a.t, object, length, msg, args...)
+}
+
+// Less asserts that the first element is less than the second
+//
+//    a.Less(1, 2)
+//    a.Less(float64(1), float64(2))
+//    a.Less("a", "b")
+func (a *Assertions) Less(e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Less(a.t, e1, e2, msgAndArgs...)
+}
+
+// LessOrEqual asserts that the first element is less than or equal to the second
+//
+//    a.LessOrEqual(1, 2)
+//    a.LessOrEqual(2, 2)
+//    a.LessOrEqual("a", "b")
+//    a.LessOrEqual("b", "b")
+func (a *Assertions) LessOrEqual(e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return LessOrEqual(a.t, e1, e2, msgAndArgs...)
+}
+
+// LessOrEqualf asserts that the first element is less than or equal to the second
+//
+//    a.LessOrEqualf(1, 2, "error message %s", "formatted")
+//    a.LessOrEqualf(2, 2, "error message %s", "formatted")
+//    a.LessOrEqualf("a", "b", "error message %s", "formatted")
+//    a.LessOrEqualf("b", "b", "error message %s", "formatted")
+func (a *Assertions) LessOrEqualf(e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return LessOrEqualf(a.t, e1, e2, msg, args...)
+}
+
+// Lessf asserts that the first element is less than the second
+//
+//    a.Lessf(1, 2, "error message %s", "formatted")
+//    a.Lessf(float64(1, "error message %s", "formatted"), float64(2))
+//    a.Lessf("a", "b", "error message %s", "formatted")
+func (a *Assertions) Lessf(e1 interface{}, e2 interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Lessf(a.t, e1, e2, msg, args...)
+}
+
+// Nil asserts that the specified object is nil.
+//
+//    a.Nil(err)
+func (a *Assertions) Nil(object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Nil(a.t, object, msgAndArgs...)
+}
+
+// Nilf asserts that the specified object is nil.
+//
+//    a.Nilf(err, "error message %s", "formatted")
+func (a *Assertions) Nilf(object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Nilf(a.t, object, msg, args...)
+}
+
+// NoError asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.NoError(err) {
+// 	   assert.Equal(t, expectedObj, actualObj)
+//   }
+func (a *Assertions) NoError(err error, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NoError(a.t, err, msgAndArgs...)
+}
+
+// NoErrorf asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.NoErrorf(err, "error message %s", "formatted") {
+// 	   assert.Equal(t, expectedObj, actualObj)
+//   }
+func (a *Assertions) NoErrorf(err error, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NoErrorf(a.t, err, msg, args...)
+}
+
+// NotContains asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    a.NotContains("Hello World", "Earth")
+//    a.NotContains(["Hello", "World"], "Earth")
+//    a.NotContains({"Hello": "World"}, "Earth")
+func (a *Assertions) NotContains(s interface{}, contains interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotContains(a.t, s, contains, msgAndArgs...)
+}
+
+// NotContainsf asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    a.NotContainsf("Hello World", "Earth", "error message %s", "formatted")
+//    a.NotContainsf(["Hello", "World"], "Earth", "error message %s", "formatted")
+//    a.NotContainsf({"Hello": "World"}, "Earth", "error message %s", "formatted")
+func (a *Assertions) NotContainsf(s interface{}, contains interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotContainsf(a.t, s, contains, msg, args...)
+}
+
+// NotEmpty asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if a.NotEmpty(obj) {
+//    assert.Equal(t, "two", obj[1])
+//  }
+func (a *Assertions) NotEmpty(object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEmpty(a.t, object, msgAndArgs...)
+}
+
+// NotEmptyf asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if a.NotEmptyf(obj, "error message %s", "formatted") {
+//    assert.Equal(t, "two", obj[1])
+//  }
+func (a *Assertions) NotEmptyf(object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEmptyf(a.t, object, msg, args...)
+}
+
+// NotEqual asserts that the specified values are NOT equal.
+//
+//    a.NotEqual(obj1, obj2)
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func (a *Assertions) NotEqual(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEqual(a.t, expected, actual, msgAndArgs...)
+}
+
+// NotEqualf asserts that the specified values are NOT equal.
+//
+//    a.NotEqualf(obj1, obj2, "error message %s", "formatted")
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func (a *Assertions) NotEqualf(expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotEqualf(a.t, expected, actual, msg, args...)
+}
+
+// NotNil asserts that the specified object is not nil.
+//
+//    a.NotNil(err)
+func (a *Assertions) NotNil(object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotNil(a.t, object, msgAndArgs...)
+}
+
+// NotNilf asserts that the specified object is not nil.
+//
+//    a.NotNilf(err, "error message %s", "formatted")
+func (a *Assertions) NotNilf(object interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotNilf(a.t, object, msg, args...)
+}
+
+// NotPanics asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   a.NotPanics(func(){ RemainCalm() })
+func (a *Assertions) NotPanics(f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotPanics(a.t, f, msgAndArgs...)
+}
+
+// NotPanicsf asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   a.NotPanicsf(func(){ RemainCalm() }, "error message %s", "formatted")
+func (a *Assertions) NotPanicsf(f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotPanicsf(a.t, f, msg, args...)
+}
+
+// NotRegexp asserts that a specified regexp does not match a string.
+//
+//  a.NotRegexp(regexp.MustCompile("starts"), "it's starting")
+//  a.NotRegexp("^start", "it's not starting")
+func (a *Assertions) NotRegexp(rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotRegexp(a.t, rx, str, msgAndArgs...)
+}
+
+// NotRegexpf asserts that a specified regexp does not match a string.
+//
+//  a.NotRegexpf(regexp.MustCompile("starts", "error message %s", "formatted"), "it's starting")
+//  a.NotRegexpf("^start", "it's not starting", "error message %s", "formatted")
+func (a *Assertions) NotRegexpf(rx interface{}, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotRegexpf(a.t, rx, str, msg, args...)
+}
+
+// NotSubset asserts that the specified list(array, slice...) contains not all
+// elements given in the specified subset(array, slice...).
+//
+//    a.NotSubset([1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]")
+func (a *Assertions) NotSubset(list interface{}, subset interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotSubset(a.t, list, subset, msgAndArgs...)
+}
+
+// NotSubsetf asserts that the specified list(array, slice...) contains not all
+// elements given in the specified subset(array, slice...).
+//
+//    a.NotSubsetf([1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]", "error message %s", "formatted")
+func (a *Assertions) NotSubsetf(list interface{}, subset interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotSubsetf(a.t, list, subset, msg, args...)
+}
+
+// NotZero asserts that i is not the zero value for its type.
+func (a *Assertions) NotZero(i interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotZero(a.t, i, msgAndArgs...)
+}
+
+// NotZerof asserts that i is not the zero value for its type.
+func (a *Assertions) NotZerof(i interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return NotZerof(a.t, i, msg, args...)
+}
+
+// Panics asserts that the code inside the specified PanicTestFunc panics.
+//
+//   a.Panics(func(){ GoCrazy() })
+func (a *Assertions) Panics(f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Panics(a.t, f, msgAndArgs...)
+}
+
+// PanicsWithValue asserts that the code inside the specified PanicTestFunc panics, and that
+// the recovered panic value equals the expected panic value.
+//
+//   a.PanicsWithValue("crazy error", func(){ GoCrazy() })
+func (a *Assertions) PanicsWithValue(expected interface{}, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return PanicsWithValue(a.t, expected, f, msgAndArgs...)
+}
+
+// PanicsWithValuef asserts that the code inside the specified PanicTestFunc panics, and that
+// the recovered panic value equals the expected panic value.
+//
+//   a.PanicsWithValuef("crazy error", func(){ GoCrazy() }, "error message %s", "formatted")
+func (a *Assertions) PanicsWithValuef(expected interface{}, f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return PanicsWithValuef(a.t, expected, f, msg, args...)
+}
+
+// Panicsf asserts that the code inside the specified PanicTestFunc panics.
+//
+//   a.Panicsf(func(){ GoCrazy() }, "error message %s", "formatted")
+func (a *Assertions) Panicsf(f PanicTestFunc, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Panicsf(a.t, f, msg, args...)
+}
+
+// Regexp asserts that a specified regexp matches a string.
+//
+//  a.Regexp(regexp.MustCompile("start"), "it's starting")
+//  a.Regexp("start...$", "it's not starting")
+func (a *Assertions) Regexp(rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Regexp(a.t, rx, str, msgAndArgs...)
+}
+
+// Regexpf asserts that a specified regexp matches a string.
+//
+//  a.Regexpf(regexp.MustCompile("start", "error message %s", "formatted"), "it's starting")
+//  a.Regexpf("start...$", "it's not starting", "error message %s", "formatted")
+func (a *Assertions) Regexpf(rx interface{}, str interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Regexpf(a.t, rx, str, msg, args...)
+}
+
+// Same asserts that two pointers reference the same object.
+//
+//    a.Same(ptr1, ptr2)
+//
+// Both arguments must be pointer variables. Pointer variable sameness is
+// determined based on the equality of both type and value.
+func (a *Assertions) Same(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Same(a.t, expected, actual, msgAndArgs...)
+}
+
+// Samef asserts that two pointers reference the same object.
+//
+//    a.Samef(ptr1, ptr2, "error message %s", "formatted")
+//
+// Both arguments must be pointer variables. Pointer variable sameness is
+// determined based on the equality of both type and value.
+func (a *Assertions) Samef(expected interface{}, actual interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Samef(a.t, expected, actual, msg, args...)
+}
+
+// Subset asserts that the specified list(array, slice...) contains all
+// elements given in the specified subset(array, slice...).
+//
+//    a.Subset([1, 2, 3], [1, 2], "But [1, 2, 3] does contain [1, 2]")
+func (a *Assertions) Subset(list interface{}, subset interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Subset(a.t, list, subset, msgAndArgs...)
+}
+
+// Subsetf asserts that the specified list(array, slice...) contains all
+// elements given in the specified subset(array, slice...).
+//
+//    a.Subsetf([1, 2, 3], [1, 2], "But [1, 2, 3] does contain [1, 2]", "error message %s", "formatted")
+func (a *Assertions) Subsetf(list interface{}, subset interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Subsetf(a.t, list, subset, msg, args...)
+}
+
+// True asserts that the specified value is true.
+//
+//    a.True(myBool)
+func (a *Assertions) True(value bool, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return True(a.t, value, msgAndArgs...)
+}
+
+// Truef asserts that the specified value is true.
+//
+//    a.Truef(myBool, "error message %s", "formatted")
+func (a *Assertions) Truef(value bool, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Truef(a.t, value, msg, args...)
+}
+
+// WithinDuration asserts that the two times are within duration delta of each other.
+//
+//   a.WithinDuration(time.Now(), time.Now(), 10*time.Second)
+func (a *Assertions) WithinDuration(expected time.Time, actual time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return WithinDuration(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// WithinDurationf asserts that the two times are within duration delta of each other.
+//
+//   a.WithinDurationf(time.Now(), time.Now(), 10*time.Second, "error message %s", "formatted")
+func (a *Assertions) WithinDurationf(expected time.Time, actual time.Time, delta time.Duration, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return WithinDurationf(a.t, expected, actual, delta, msg, args...)
+}
+
+// Zero asserts that i is the zero value for its type.
+func (a *Assertions) Zero(i interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Zero(a.t, i, msgAndArgs...)
+}
+
+// Zerof asserts that i is the zero value for its type.
+func (a *Assertions) Zerof(i interface{}, msg string, args ...interface{}) bool {
+	if h, ok := a.t.(tHelper); ok {
+		h.Helper()
+	}
+	return Zerof(a.t, i, msg, args...)
+}
diff --git a/vendor/github.com/stretchr/testify/assert/assertion_forward.go.tmpl b/vendor/github.com/stretchr/testify/assert/assertion_forward.go.tmpl
new file mode 100644
index 0000000..188bb9e
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertion_forward.go.tmpl
@@ -0,0 +1,5 @@
+{{.CommentWithoutT "a"}}
+func (a *Assertions) {{.DocInfo.Name}}({{.Params}}) bool {
+	if h, ok := a.t.(tHelper); ok { h.Helper() }
+	return {{.DocInfo.Name}}(a.t, {{.ForwardedParams}})
+}
diff --git a/vendor/github.com/stretchr/testify/assert/assertion_order.go b/vendor/github.com/stretchr/testify/assert/assertion_order.go
new file mode 100644
index 0000000..15a486c
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertion_order.go
@@ -0,0 +1,309 @@
+package assert
+
+import (
+	"fmt"
+	"reflect"
+)
+
+func compare(obj1, obj2 interface{}, kind reflect.Kind) (int, bool) {
+	switch kind {
+	case reflect.Int:
+		{
+			intobj1 := obj1.(int)
+			intobj2 := obj2.(int)
+			if intobj1 > intobj2 {
+				return -1, true
+			}
+			if intobj1 == intobj2 {
+				return 0, true
+			}
+			if intobj1 < intobj2 {
+				return 1, true
+			}
+		}
+	case reflect.Int8:
+		{
+			int8obj1 := obj1.(int8)
+			int8obj2 := obj2.(int8)
+			if int8obj1 > int8obj2 {
+				return -1, true
+			}
+			if int8obj1 == int8obj2 {
+				return 0, true
+			}
+			if int8obj1 < int8obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Int16:
+		{
+			int16obj1 := obj1.(int16)
+			int16obj2 := obj2.(int16)
+			if int16obj1 > int16obj2 {
+				return -1, true
+			}
+			if int16obj1 == int16obj2 {
+				return 0, true
+			}
+			if int16obj1 < int16obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Int32:
+		{
+			int32obj1 := obj1.(int32)
+			int32obj2 := obj2.(int32)
+			if int32obj1 > int32obj2 {
+				return -1, true
+			}
+			if int32obj1 == int32obj2 {
+				return 0, true
+			}
+			if int32obj1 < int32obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Int64:
+		{
+			int64obj1 := obj1.(int64)
+			int64obj2 := obj2.(int64)
+			if int64obj1 > int64obj2 {
+				return -1, true
+			}
+			if int64obj1 == int64obj2 {
+				return 0, true
+			}
+			if int64obj1 < int64obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Uint:
+		{
+			uintobj1 := obj1.(uint)
+			uintobj2 := obj2.(uint)
+			if uintobj1 > uintobj2 {
+				return -1, true
+			}
+			if uintobj1 == uintobj2 {
+				return 0, true
+			}
+			if uintobj1 < uintobj2 {
+				return 1, true
+			}
+		}
+	case reflect.Uint8:
+		{
+			uint8obj1 := obj1.(uint8)
+			uint8obj2 := obj2.(uint8)
+			if uint8obj1 > uint8obj2 {
+				return -1, true
+			}
+			if uint8obj1 == uint8obj2 {
+				return 0, true
+			}
+			if uint8obj1 < uint8obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Uint16:
+		{
+			uint16obj1 := obj1.(uint16)
+			uint16obj2 := obj2.(uint16)
+			if uint16obj1 > uint16obj2 {
+				return -1, true
+			}
+			if uint16obj1 == uint16obj2 {
+				return 0, true
+			}
+			if uint16obj1 < uint16obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Uint32:
+		{
+			uint32obj1 := obj1.(uint32)
+			uint32obj2 := obj2.(uint32)
+			if uint32obj1 > uint32obj2 {
+				return -1, true
+			}
+			if uint32obj1 == uint32obj2 {
+				return 0, true
+			}
+			if uint32obj1 < uint32obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Uint64:
+		{
+			uint64obj1 := obj1.(uint64)
+			uint64obj2 := obj2.(uint64)
+			if uint64obj1 > uint64obj2 {
+				return -1, true
+			}
+			if uint64obj1 == uint64obj2 {
+				return 0, true
+			}
+			if uint64obj1 < uint64obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Float32:
+		{
+			float32obj1 := obj1.(float32)
+			float32obj2 := obj2.(float32)
+			if float32obj1 > float32obj2 {
+				return -1, true
+			}
+			if float32obj1 == float32obj2 {
+				return 0, true
+			}
+			if float32obj1 < float32obj2 {
+				return 1, true
+			}
+		}
+	case reflect.Float64:
+		{
+			float64obj1 := obj1.(float64)
+			float64obj2 := obj2.(float64)
+			if float64obj1 > float64obj2 {
+				return -1, true
+			}
+			if float64obj1 == float64obj2 {
+				return 0, true
+			}
+			if float64obj1 < float64obj2 {
+				return 1, true
+			}
+		}
+	case reflect.String:
+		{
+			stringobj1 := obj1.(string)
+			stringobj2 := obj2.(string)
+			if stringobj1 > stringobj2 {
+				return -1, true
+			}
+			if stringobj1 == stringobj2 {
+				return 0, true
+			}
+			if stringobj1 < stringobj2 {
+				return 1, true
+			}
+		}
+	}
+
+	return 0, false
+}
+
+// Greater asserts that the first element is greater than the second
+//
+//    assert.Greater(t, 2, 1)
+//    assert.Greater(t, float64(2), float64(1))
+//    assert.Greater(t, "b", "a")
+func Greater(t TestingT, e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	e1Kind := reflect.ValueOf(e1).Kind()
+	e2Kind := reflect.ValueOf(e2).Kind()
+	if e1Kind != e2Kind {
+		return Fail(t, "Elements should be the same type", msgAndArgs...)
+	}
+
+	res, isComparable := compare(e1, e2, e1Kind)
+	if !isComparable {
+		return Fail(t, fmt.Sprintf("Can not compare type \"%s\"", reflect.TypeOf(e1)), msgAndArgs...)
+	}
+
+	if res != -1 {
+		return Fail(t, fmt.Sprintf("\"%v\" is not greater than \"%v\"", e1, e2), msgAndArgs...)
+	}
+
+	return true
+}
+
+// GreaterOrEqual asserts that the first element is greater than or equal to the second
+//
+//    assert.GreaterOrEqual(t, 2, 1)
+//    assert.GreaterOrEqual(t, 2, 2)
+//    assert.GreaterOrEqual(t, "b", "a")
+//    assert.GreaterOrEqual(t, "b", "b")
+func GreaterOrEqual(t TestingT, e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	e1Kind := reflect.ValueOf(e1).Kind()
+	e2Kind := reflect.ValueOf(e2).Kind()
+	if e1Kind != e2Kind {
+		return Fail(t, "Elements should be the same type", msgAndArgs...)
+	}
+
+	res, isComparable := compare(e1, e2, e1Kind)
+	if !isComparable {
+		return Fail(t, fmt.Sprintf("Can not compare type \"%s\"", reflect.TypeOf(e1)), msgAndArgs...)
+	}
+
+	if res != -1 && res != 0 {
+		return Fail(t, fmt.Sprintf("\"%v\" is not greater than or equal to \"%v\"", e1, e2), msgAndArgs...)
+	}
+
+	return true
+}
+
+// Less asserts that the first element is less than the second
+//
+//    assert.Less(t, 1, 2)
+//    assert.Less(t, float64(1), float64(2))
+//    assert.Less(t, "a", "b")
+func Less(t TestingT, e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	e1Kind := reflect.ValueOf(e1).Kind()
+	e2Kind := reflect.ValueOf(e2).Kind()
+	if e1Kind != e2Kind {
+		return Fail(t, "Elements should be the same type", msgAndArgs...)
+	}
+
+	res, isComparable := compare(e1, e2, e1Kind)
+	if !isComparable {
+		return Fail(t, fmt.Sprintf("Can not compare type \"%s\"", reflect.TypeOf(e1)), msgAndArgs...)
+	}
+
+	if res != 1 {
+		return Fail(t, fmt.Sprintf("\"%v\" is not less than \"%v\"", e1, e2), msgAndArgs...)
+	}
+
+	return true
+}
+
+// LessOrEqual asserts that the first element is less than or equal to the second
+//
+//    assert.LessOrEqual(t, 1, 2)
+//    assert.LessOrEqual(t, 2, 2)
+//    assert.LessOrEqual(t, "a", "b")
+//    assert.LessOrEqual(t, "b", "b")
+func LessOrEqual(t TestingT, e1 interface{}, e2 interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	e1Kind := reflect.ValueOf(e1).Kind()
+	e2Kind := reflect.ValueOf(e2).Kind()
+	if e1Kind != e2Kind {
+		return Fail(t, "Elements should be the same type", msgAndArgs...)
+	}
+
+	res, isComparable := compare(e1, e2, e1Kind)
+	if !isComparable {
+		return Fail(t, fmt.Sprintf("Can not compare type \"%s\"", reflect.TypeOf(e1)), msgAndArgs...)
+	}
+
+	if res != 1 && res != 0 {
+		return Fail(t, fmt.Sprintf("\"%v\" is not less than or equal to \"%v\"", e1, e2), msgAndArgs...)
+	}
+
+	return true
+}
diff --git a/vendor/github.com/stretchr/testify/assert/assertions.go b/vendor/github.com/stretchr/testify/assert/assertions.go
new file mode 100644
index 0000000..044da8b
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/assertions.go
@@ -0,0 +1,1498 @@
+package assert
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"os"
+	"reflect"
+	"regexp"
+	"runtime"
+	"strings"
+	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/pmezard/go-difflib/difflib"
+	yaml "gopkg.in/yaml.v2"
+)
+
+//go:generate go run ../_codegen/main.go -output-package=assert -template=assertion_format.go.tmpl
+
+// TestingT is an interface wrapper around *testing.T
+type TestingT interface {
+	Errorf(format string, args ...interface{})
+}
+
+// ComparisonAssertionFunc is a common function prototype when comparing two values.  Can be useful
+// for table driven tests.
+type ComparisonAssertionFunc func(TestingT, interface{}, interface{}, ...interface{}) bool
+
+// ValueAssertionFunc is a common function prototype when validating a single value.  Can be useful
+// for table driven tests.
+type ValueAssertionFunc func(TestingT, interface{}, ...interface{}) bool
+
+// BoolAssertionFunc is a common function prototype when validating a bool value.  Can be useful
+// for table driven tests.
+type BoolAssertionFunc func(TestingT, bool, ...interface{}) bool
+
+// ErrorAssertionFunc is a common function prototype when validating an error value.  Can be useful
+// for table driven tests.
+type ErrorAssertionFunc func(TestingT, error, ...interface{}) bool
+
+// Comparison a custom function that returns true on success and false on failure
+type Comparison func() (success bool)
+
+/*
+	Helper functions
+*/
+
+// ObjectsAreEqual determines if two objects are considered equal.
+//
+// This function does no assertion of any kind.
+func ObjectsAreEqual(expected, actual interface{}) bool {
+	if expected == nil || actual == nil {
+		return expected == actual
+	}
+
+	exp, ok := expected.([]byte)
+	if !ok {
+		return reflect.DeepEqual(expected, actual)
+	}
+
+	act, ok := actual.([]byte)
+	if !ok {
+		return false
+	}
+	if exp == nil || act == nil {
+		return exp == nil && act == nil
+	}
+	return bytes.Equal(exp, act)
+}
+
+// ObjectsAreEqualValues gets whether two objects are equal, or if their
+// values are equal.
+func ObjectsAreEqualValues(expected, actual interface{}) bool {
+	if ObjectsAreEqual(expected, actual) {
+		return true
+	}
+
+	actualType := reflect.TypeOf(actual)
+	if actualType == nil {
+		return false
+	}
+	expectedValue := reflect.ValueOf(expected)
+	if expectedValue.IsValid() && expectedValue.Type().ConvertibleTo(actualType) {
+		// Attempt comparison after type conversion
+		return reflect.DeepEqual(expectedValue.Convert(actualType).Interface(), actual)
+	}
+
+	return false
+}
+
+/* CallerInfo is necessary because the assert functions use the testing object
+internally, causing it to print the file:line of the assert method, rather than where
+the problem actually occurred in calling code.*/
+
+// CallerInfo returns an array of strings containing the file and line number
+// of each stack frame leading from the current test to the assert call that
+// failed.
+func CallerInfo() []string {
+
+	pc := uintptr(0)
+	file := ""
+	line := 0
+	ok := false
+	name := ""
+
+	callers := []string{}
+	for i := 0; ; i++ {
+		pc, file, line, ok = runtime.Caller(i)
+		if !ok {
+			// The breaks below failed to terminate the loop, and we ran off the
+			// end of the call stack.
+			break
+		}
+
+		// This is a huge edge case, but it will panic if this is the case, see #180
+		if file == "<autogenerated>" {
+			break
+		}
+
+		f := runtime.FuncForPC(pc)
+		if f == nil {
+			break
+		}
+		name = f.Name()
+
+		// testing.tRunner is the standard library function that calls
+		// tests. Subtests are called directly by tRunner, without going through
+		// the Test/Benchmark/Example function that contains the t.Run calls, so
+		// with subtests we should break when we hit tRunner, without adding it
+		// to the list of callers.
+		if name == "testing.tRunner" {
+			break
+		}
+
+		parts := strings.Split(file, "/")
+		file = parts[len(parts)-1]
+		if len(parts) > 1 {
+			dir := parts[len(parts)-2]
+			if (dir != "assert" && dir != "mock" && dir != "require") || file == "mock_test.go" {
+				callers = append(callers, fmt.Sprintf("%s:%d", file, line))
+			}
+		}
+
+		// Drop the package
+		segments := strings.Split(name, ".")
+		name = segments[len(segments)-1]
+		if isTest(name, "Test") ||
+			isTest(name, "Benchmark") ||
+			isTest(name, "Example") {
+			break
+		}
+	}
+
+	return callers
+}
+
+// Stolen from the `go test` tool.
+// isTest tells whether name looks like a test (or benchmark, according to prefix).
+// It is a Test (say) if there is a character after Test that is not a lower-case letter.
+// We don't want TesticularCancer.
+func isTest(name, prefix string) bool {
+	if !strings.HasPrefix(name, prefix) {
+		return false
+	}
+	if len(name) == len(prefix) { // "Test" is ok
+		return true
+	}
+	rune, _ := utf8.DecodeRuneInString(name[len(prefix):])
+	return !unicode.IsLower(rune)
+}
+
+func messageFromMsgAndArgs(msgAndArgs ...interface{}) string {
+	if len(msgAndArgs) == 0 || msgAndArgs == nil {
+		return ""
+	}
+	if len(msgAndArgs) == 1 {
+		msg := msgAndArgs[0]
+		if msgAsStr, ok := msg.(string); ok {
+			return msgAsStr
+		}
+		return fmt.Sprintf("%+v", msg)
+	}
+	if len(msgAndArgs) > 1 {
+		return fmt.Sprintf(msgAndArgs[0].(string), msgAndArgs[1:]...)
+	}
+	return ""
+}
+
+// Aligns the provided message so that all lines after the first line start at the same location as the first line.
+// Assumes that the first line starts at the correct location (after carriage return, tab, label, spacer and tab).
+// The longestLabelLen parameter specifies the length of the longest label in the output (required becaues this is the
+// basis on which the alignment occurs).
+func indentMessageLines(message string, longestLabelLen int) string {
+	outBuf := new(bytes.Buffer)
+
+	for i, scanner := 0, bufio.NewScanner(strings.NewReader(message)); scanner.Scan(); i++ {
+		// no need to align first line because it starts at the correct location (after the label)
+		if i != 0 {
+			// append alignLen+1 spaces to align with "{{longestLabel}}:" before adding tab
+			outBuf.WriteString("\n\t" + strings.Repeat(" ", longestLabelLen+1) + "\t")
+		}
+		outBuf.WriteString(scanner.Text())
+	}
+
+	return outBuf.String()
+}
+
+type failNower interface {
+	FailNow()
+}
+
+// FailNow fails test
+func FailNow(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	Fail(t, failureMessage, msgAndArgs...)
+
+	// We cannot extend TestingT with FailNow() and
+	// maintain backwards compatibility, so we fallback
+	// to panicking when FailNow is not available in
+	// TestingT.
+	// See issue #263
+
+	if t, ok := t.(failNower); ok {
+		t.FailNow()
+	} else {
+		panic("test failed and t is missing `FailNow()`")
+	}
+	return false
+}
+
+// Fail reports a failure through
+func Fail(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	content := []labeledContent{
+		{"Error Trace", strings.Join(CallerInfo(), "\n\t\t\t")},
+		{"Error", failureMessage},
+	}
+
+	// Add test name if the Go version supports it
+	if n, ok := t.(interface {
+		Name() string
+	}); ok {
+		content = append(content, labeledContent{"Test", n.Name()})
+	}
+
+	message := messageFromMsgAndArgs(msgAndArgs...)
+	if len(message) > 0 {
+		content = append(content, labeledContent{"Messages", message})
+	}
+
+	t.Errorf("\n%s", ""+labeledOutput(content...))
+
+	return false
+}
+
+type labeledContent struct {
+	label   string
+	content string
+}
+
+// labeledOutput returns a string consisting of the provided labeledContent. Each labeled output is appended in the following manner:
+//
+//   \t{{label}}:{{align_spaces}}\t{{content}}\n
+//
+// The initial carriage return is required to undo/erase any padding added by testing.T.Errorf. The "\t{{label}}:" is for the label.
+// If a label is shorter than the longest label provided, padding spaces are added to make all the labels match in length. Once this
+// alignment is achieved, "\t{{content}}\n" is added for the output.
+//
+// If the content of the labeledOutput contains line breaks, the subsequent lines are aligned so that they start at the same location as the first line.
+func labeledOutput(content ...labeledContent) string {
+	longestLabel := 0
+	for _, v := range content {
+		if len(v.label) > longestLabel {
+			longestLabel = len(v.label)
+		}
+	}
+	var output string
+	for _, v := range content {
+		output += "\t" + v.label + ":" + strings.Repeat(" ", longestLabel-len(v.label)) + "\t" + indentMessageLines(v.content, longestLabel) + "\n"
+	}
+	return output
+}
+
+// Implements asserts that an object is implemented by the specified interface.
+//
+//    assert.Implements(t, (*MyInterface)(nil), new(MyObject))
+func Implements(t TestingT, interfaceObject interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	interfaceType := reflect.TypeOf(interfaceObject).Elem()
+
+	if object == nil {
+		return Fail(t, fmt.Sprintf("Cannot check if nil implements %v", interfaceType), msgAndArgs...)
+	}
+	if !reflect.TypeOf(object).Implements(interfaceType) {
+		return Fail(t, fmt.Sprintf("%T must implement %v", object, interfaceType), msgAndArgs...)
+	}
+
+	return true
+}
+
+// IsType asserts that the specified objects are of the same type.
+func IsType(t TestingT, expectedType interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if !ObjectsAreEqual(reflect.TypeOf(object), reflect.TypeOf(expectedType)) {
+		return Fail(t, fmt.Sprintf("Object expected to be of type %v, but was %v", reflect.TypeOf(expectedType), reflect.TypeOf(object)), msgAndArgs...)
+	}
+
+	return true
+}
+
+// Equal asserts that two objects are equal.
+//
+//    assert.Equal(t, 123, 123)
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses). Function equality
+// cannot be determined and will always fail.
+func Equal(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if err := validateEqualArgs(expected, actual); err != nil {
+		return Fail(t, fmt.Sprintf("Invalid operation: %#v == %#v (%s)",
+			expected, actual, err), msgAndArgs...)
+	}
+
+	if !ObjectsAreEqual(expected, actual) {
+		diff := diff(expected, actual)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"actual  : %s%s", expected, actual, diff), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// Same asserts that two pointers reference the same object.
+//
+//    assert.Same(t, ptr1, ptr2)
+//
+// Both arguments must be pointer variables. Pointer variable sameness is
+// determined based on the equality of both type and value.
+func Same(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	expectedPtr, actualPtr := reflect.ValueOf(expected), reflect.ValueOf(actual)
+	if expectedPtr.Kind() != reflect.Ptr || actualPtr.Kind() != reflect.Ptr {
+		return Fail(t, "Invalid operation: both arguments must be pointers", msgAndArgs...)
+	}
+
+	expectedType, actualType := reflect.TypeOf(expected), reflect.TypeOf(actual)
+	if expectedType != actualType {
+		return Fail(t, fmt.Sprintf("Pointer expected to be of type %v, but was %v",
+			expectedType, actualType), msgAndArgs...)
+	}
+
+	if expected != actual {
+		return Fail(t, fmt.Sprintf("Not same: \n"+
+			"expected: %p %#v\n"+
+			"actual  : %p %#v", expected, expected, actual, actual), msgAndArgs...)
+	}
+
+	return true
+}
+
+// formatUnequalValues takes two values of arbitrary types and returns string
+// representations appropriate to be presented to the user.
+//
+// If the values are not of like type, the returned strings will be prefixed
+// with the type name, and the value will be enclosed in parenthesis similar
+// to a type conversion in the Go grammar.
+func formatUnequalValues(expected, actual interface{}) (e string, a string) {
+	if reflect.TypeOf(expected) != reflect.TypeOf(actual) {
+		return fmt.Sprintf("%T(%#v)", expected, expected),
+			fmt.Sprintf("%T(%#v)", actual, actual)
+	}
+
+	return fmt.Sprintf("%#v", expected),
+		fmt.Sprintf("%#v", actual)
+}
+
+// EqualValues asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    assert.EqualValues(t, uint32(123), int32(123))
+func EqualValues(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if !ObjectsAreEqualValues(expected, actual) {
+		diff := diff(expected, actual)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"actual  : %s%s", expected, actual, diff), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// Exactly asserts that two objects are equal in value and type.
+//
+//    assert.Exactly(t, int32(123), int64(123))
+func Exactly(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	aType := reflect.TypeOf(expected)
+	bType := reflect.TypeOf(actual)
+
+	if aType != bType {
+		return Fail(t, fmt.Sprintf("Types expected to match exactly\n\t%v != %v", aType, bType), msgAndArgs...)
+	}
+
+	return Equal(t, expected, actual, msgAndArgs...)
+
+}
+
+// NotNil asserts that the specified object is not nil.
+//
+//    assert.NotNil(t, err)
+func NotNil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if !isNil(object) {
+		return true
+	}
+	return Fail(t, "Expected value not to be nil.", msgAndArgs...)
+}
+
+// containsKind checks if a specified kind in the slice of kinds.
+func containsKind(kinds []reflect.Kind, kind reflect.Kind) bool {
+	for i := 0; i < len(kinds); i++ {
+		if kind == kinds[i] {
+			return true
+		}
+	}
+
+	return false
+}
+
+// isNil checks if a specified object is nil or not, without Failing.
+func isNil(object interface{}) bool {
+	if object == nil {
+		return true
+	}
+
+	value := reflect.ValueOf(object)
+	kind := value.Kind()
+	isNilableKind := containsKind(
+		[]reflect.Kind{
+			reflect.Chan, reflect.Func,
+			reflect.Interface, reflect.Map,
+			reflect.Ptr, reflect.Slice},
+		kind)
+
+	if isNilableKind && value.IsNil() {
+		return true
+	}
+
+	return false
+}
+
+// Nil asserts that the specified object is nil.
+//
+//    assert.Nil(t, err)
+func Nil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if isNil(object) {
+		return true
+	}
+	return Fail(t, fmt.Sprintf("Expected nil, but got: %#v", object), msgAndArgs...)
+}
+
+// isEmpty gets whether the specified object is considered empty or not.
+func isEmpty(object interface{}) bool {
+
+	// get nil case out of the way
+	if object == nil {
+		return true
+	}
+
+	objValue := reflect.ValueOf(object)
+
+	switch objValue.Kind() {
+	// collection types are empty when they have no element
+	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
+		return objValue.Len() == 0
+		// pointers are empty if nil or if the value they point to is empty
+	case reflect.Ptr:
+		if objValue.IsNil() {
+			return true
+		}
+		deref := objValue.Elem().Interface()
+		return isEmpty(deref)
+		// for all other types, compare against the zero value
+	default:
+		zero := reflect.Zero(objValue.Type())
+		return reflect.DeepEqual(object, zero.Interface())
+	}
+}
+
+// Empty asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  assert.Empty(t, obj)
+func Empty(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	pass := isEmpty(object)
+	if !pass {
+		Fail(t, fmt.Sprintf("Should be empty, but was %v", object), msgAndArgs...)
+	}
+
+	return pass
+
+}
+
+// NotEmpty asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if assert.NotEmpty(t, obj) {
+//    assert.Equal(t, "two", obj[1])
+//  }
+func NotEmpty(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	pass := !isEmpty(object)
+	if !pass {
+		Fail(t, fmt.Sprintf("Should NOT be empty, but was %v", object), msgAndArgs...)
+	}
+
+	return pass
+
+}
+
+// getLen try to get length of object.
+// return (false, 0) if impossible.
+func getLen(x interface{}) (ok bool, length int) {
+	v := reflect.ValueOf(x)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+	return true, v.Len()
+}
+
+// Len asserts that the specified object has specific length.
+// Len also fails if the object has a type that len() not accept.
+//
+//    assert.Len(t, mySlice, 3)
+func Len(t TestingT, object interface{}, length int, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	ok, l := getLen(object)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", object), msgAndArgs...)
+	}
+
+	if l != length {
+		return Fail(t, fmt.Sprintf("\"%s\" should have %d item(s), but has %d", object, length, l), msgAndArgs...)
+	}
+	return true
+}
+
+// True asserts that the specified value is true.
+//
+//    assert.True(t, myBool)
+func True(t TestingT, value bool, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if h, ok := t.(interface {
+		Helper()
+	}); ok {
+		h.Helper()
+	}
+
+	if value != true {
+		return Fail(t, "Should be true", msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// False asserts that the specified value is false.
+//
+//    assert.False(t, myBool)
+func False(t TestingT, value bool, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if value != false {
+		return Fail(t, "Should be false", msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// NotEqual asserts that the specified values are NOT equal.
+//
+//    assert.NotEqual(t, obj1, obj2)
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func NotEqual(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if err := validateEqualArgs(expected, actual); err != nil {
+		return Fail(t, fmt.Sprintf("Invalid operation: %#v != %#v (%s)",
+			expected, actual, err), msgAndArgs...)
+	}
+
+	if ObjectsAreEqual(expected, actual) {
+		return Fail(t, fmt.Sprintf("Should not be: %#v\n", actual), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// containsElement try loop over the list check if the list includes the element.
+// return (false, false) if impossible.
+// return (true, false) if element was not found.
+// return (true, true) if element was found.
+func includeElement(list interface{}, element interface{}) (ok, found bool) {
+
+	listValue := reflect.ValueOf(list)
+	listKind := reflect.TypeOf(list).Kind()
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+			found = false
+		}
+	}()
+
+	if listKind == reflect.String {
+		elementValue := reflect.ValueOf(element)
+		return true, strings.Contains(listValue.String(), elementValue.String())
+	}
+
+	if listKind == reflect.Map {
+		mapKeys := listValue.MapKeys()
+		for i := 0; i < len(mapKeys); i++ {
+			if ObjectsAreEqual(mapKeys[i].Interface(), element) {
+				return true, true
+			}
+		}
+		return true, false
+	}
+
+	for i := 0; i < listValue.Len(); i++ {
+		if ObjectsAreEqual(listValue.Index(i).Interface(), element) {
+			return true, true
+		}
+	}
+	return true, false
+
+}
+
+// Contains asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    assert.Contains(t, "Hello World", "World")
+//    assert.Contains(t, ["Hello", "World"], "World")
+//    assert.Contains(t, {"Hello": "World"}, "Hello")
+func Contains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	ok, found := includeElement(s, contains)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", s), msgAndArgs...)
+	}
+	if !found {
+		return Fail(t, fmt.Sprintf("\"%s\" does not contain \"%s\"", s, contains), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// NotContains asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    assert.NotContains(t, "Hello World", "Earth")
+//    assert.NotContains(t, ["Hello", "World"], "Earth")
+//    assert.NotContains(t, {"Hello": "World"}, "Earth")
+func NotContains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	ok, found := includeElement(s, contains)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", s), msgAndArgs...)
+	}
+	if found {
+		return Fail(t, fmt.Sprintf("\"%s\" should not contain \"%s\"", s, contains), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// Subset asserts that the specified list(array, slice...) contains all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.Subset(t, [1, 2, 3], [1, 2], "But [1, 2, 3] does contain [1, 2]")
+func Subset(t TestingT, list, subset interface{}, msgAndArgs ...interface{}) (ok bool) {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if subset == nil {
+		return true // we consider nil to be equal to the nil set
+	}
+
+	subsetValue := reflect.ValueOf(subset)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+
+	listKind := reflect.TypeOf(list).Kind()
+	subsetKind := reflect.TypeOf(subset).Kind()
+
+	if listKind != reflect.Array && listKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", list, listKind), msgAndArgs...)
+	}
+
+	if subsetKind != reflect.Array && subsetKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", subset, subsetKind), msgAndArgs...)
+	}
+
+	for i := 0; i < subsetValue.Len(); i++ {
+		element := subsetValue.Index(i).Interface()
+		ok, found := includeElement(list, element)
+		if !ok {
+			return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", list), msgAndArgs...)
+		}
+		if !found {
+			return Fail(t, fmt.Sprintf("\"%s\" does not contain \"%s\"", list, element), msgAndArgs...)
+		}
+	}
+
+	return true
+}
+
+// NotSubset asserts that the specified list(array, slice...) contains not all
+// elements given in the specified subset(array, slice...).
+//
+//    assert.NotSubset(t, [1, 3, 4], [1, 2], "But [1, 3, 4] does not contain [1, 2]")
+func NotSubset(t TestingT, list, subset interface{}, msgAndArgs ...interface{}) (ok bool) {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if subset == nil {
+		return Fail(t, fmt.Sprintf("nil is the empty set which is a subset of every set"), msgAndArgs...)
+	}
+
+	subsetValue := reflect.ValueOf(subset)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+
+	listKind := reflect.TypeOf(list).Kind()
+	subsetKind := reflect.TypeOf(subset).Kind()
+
+	if listKind != reflect.Array && listKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", list, listKind), msgAndArgs...)
+	}
+
+	if subsetKind != reflect.Array && subsetKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", subset, subsetKind), msgAndArgs...)
+	}
+
+	for i := 0; i < subsetValue.Len(); i++ {
+		element := subsetValue.Index(i).Interface()
+		ok, found := includeElement(list, element)
+		if !ok {
+			return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", list), msgAndArgs...)
+		}
+		if !found {
+			return true
+		}
+	}
+
+	return Fail(t, fmt.Sprintf("%q is a subset of %q", subset, list), msgAndArgs...)
+}
+
+// ElementsMatch asserts that the specified listA(array, slice...) is equal to specified
+// listB(array, slice...) ignoring the order of the elements. If there are duplicate elements,
+// the number of appearances of each of them in both lists should match.
+//
+// assert.ElementsMatch(t, [1, 3, 2, 3], [1, 3, 3, 2])
+func ElementsMatch(t TestingT, listA, listB interface{}, msgAndArgs ...interface{}) (ok bool) {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if isEmpty(listA) && isEmpty(listB) {
+		return true
+	}
+
+	aKind := reflect.TypeOf(listA).Kind()
+	bKind := reflect.TypeOf(listB).Kind()
+
+	if aKind != reflect.Array && aKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", listA, aKind), msgAndArgs...)
+	}
+
+	if bKind != reflect.Array && bKind != reflect.Slice {
+		return Fail(t, fmt.Sprintf("%q has an unsupported type %s", listB, bKind), msgAndArgs...)
+	}
+
+	aValue := reflect.ValueOf(listA)
+	bValue := reflect.ValueOf(listB)
+
+	aLen := aValue.Len()
+	bLen := bValue.Len()
+
+	if aLen != bLen {
+		return Fail(t, fmt.Sprintf("lengths don't match: %d != %d", aLen, bLen), msgAndArgs...)
+	}
+
+	// Mark indexes in bValue that we already used
+	visited := make([]bool, bLen)
+	for i := 0; i < aLen; i++ {
+		element := aValue.Index(i).Interface()
+		found := false
+		for j := 0; j < bLen; j++ {
+			if visited[j] {
+				continue
+			}
+			if ObjectsAreEqual(bValue.Index(j).Interface(), element) {
+				visited[j] = true
+				found = true
+				break
+			}
+		}
+		if !found {
+			return Fail(t, fmt.Sprintf("element %s appears more times in %s than in %s", element, aValue, bValue), msgAndArgs...)
+		}
+	}
+
+	return true
+}
+
+// Condition uses a Comparison to assert a complex condition.
+func Condition(t TestingT, comp Comparison, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	result := comp()
+	if !result {
+		Fail(t, "Condition failed!", msgAndArgs...)
+	}
+	return result
+}
+
+// PanicTestFunc defines a func that should be passed to the assert.Panics and assert.NotPanics
+// methods, and represents a simple func that takes no arguments, and returns nothing.
+type PanicTestFunc func()
+
+// didPanic returns true if the function passed to it panics. Otherwise, it returns false.
+func didPanic(f PanicTestFunc) (bool, interface{}) {
+
+	didPanic := false
+	var message interface{}
+	func() {
+
+		defer func() {
+			if message = recover(); message != nil {
+				didPanic = true
+			}
+		}()
+
+		// call the target function
+		f()
+
+	}()
+
+	return didPanic, message
+
+}
+
+// Panics asserts that the code inside the specified PanicTestFunc panics.
+//
+//   assert.Panics(t, func(){ GoCrazy() })
+func Panics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if funcDidPanic, panicValue := didPanic(f); !funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should panic\n\tPanic value:\t%#v", f, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
+// PanicsWithValue asserts that the code inside the specified PanicTestFunc panics, and that
+// the recovered panic value equals the expected panic value.
+//
+//   assert.PanicsWithValue(t, "crazy error", func(){ GoCrazy() })
+func PanicsWithValue(t TestingT, expected interface{}, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	funcDidPanic, panicValue := didPanic(f)
+	if !funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should panic\n\tPanic value:\t%#v", f, panicValue), msgAndArgs...)
+	}
+	if panicValue != expected {
+		return Fail(t, fmt.Sprintf("func %#v should panic with value:\t%#v\n\tPanic value:\t%#v", f, expected, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
+// NotPanics asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   assert.NotPanics(t, func(){ RemainCalm() })
+func NotPanics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if funcDidPanic, panicValue := didPanic(f); funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should not panic\n\tPanic value:\t%v", f, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
+// WithinDuration asserts that the two times are within duration delta of each other.
+//
+//   assert.WithinDuration(t, time.Now(), time.Now(), 10*time.Second)
+func WithinDuration(t TestingT, expected, actual time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	dt := expected.Sub(actual)
+	if dt < -delta || dt > delta {
+		return Fail(t, fmt.Sprintf("Max difference between %v and %v allowed is %v, but difference was %v", expected, actual, delta, dt), msgAndArgs...)
+	}
+
+	return true
+}
+
+func toFloat(x interface{}) (float64, bool) {
+	var xf float64
+	xok := true
+
+	switch xn := x.(type) {
+	case uint8:
+		xf = float64(xn)
+	case uint16:
+		xf = float64(xn)
+	case uint32:
+		xf = float64(xn)
+	case uint64:
+		xf = float64(xn)
+	case int:
+		xf = float64(xn)
+	case int8:
+		xf = float64(xn)
+	case int16:
+		xf = float64(xn)
+	case int32:
+		xf = float64(xn)
+	case int64:
+		xf = float64(xn)
+	case float32:
+		xf = float64(xn)
+	case float64:
+		xf = float64(xn)
+	case time.Duration:
+		xf = float64(xn)
+	default:
+		xok = false
+	}
+
+	return xf, xok
+}
+
+// InDelta asserts that the two numerals are within delta of each other.
+//
+// 	 assert.InDelta(t, math.Pi, (22 / 7.0), 0.01)
+func InDelta(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	af, aok := toFloat(expected)
+	bf, bok := toFloat(actual)
+
+	if !aok || !bok {
+		return Fail(t, fmt.Sprintf("Parameters must be numerical"), msgAndArgs...)
+	}
+
+	if math.IsNaN(af) {
+		return Fail(t, fmt.Sprintf("Expected must not be NaN"), msgAndArgs...)
+	}
+
+	if math.IsNaN(bf) {
+		return Fail(t, fmt.Sprintf("Expected %v with delta %v, but was NaN", expected, delta), msgAndArgs...)
+	}
+
+	dt := af - bf
+	if dt < -delta || dt > delta {
+		return Fail(t, fmt.Sprintf("Max difference between %v and %v allowed is %v, but difference was %v", expected, actual, delta, dt), msgAndArgs...)
+	}
+
+	return true
+}
+
+// InDeltaSlice is the same as InDelta, except it compares two slices.
+func InDeltaSlice(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if expected == nil || actual == nil ||
+		reflect.TypeOf(actual).Kind() != reflect.Slice ||
+		reflect.TypeOf(expected).Kind() != reflect.Slice {
+		return Fail(t, fmt.Sprintf("Parameters must be slice"), msgAndArgs...)
+	}
+
+	actualSlice := reflect.ValueOf(actual)
+	expectedSlice := reflect.ValueOf(expected)
+
+	for i := 0; i < actualSlice.Len(); i++ {
+		result := InDelta(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), delta, msgAndArgs...)
+		if !result {
+			return result
+		}
+	}
+
+	return true
+}
+
+// InDeltaMapValues is the same as InDelta, but it compares all values between two maps. Both maps must have exactly the same keys.
+func InDeltaMapValues(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if expected == nil || actual == nil ||
+		reflect.TypeOf(actual).Kind() != reflect.Map ||
+		reflect.TypeOf(expected).Kind() != reflect.Map {
+		return Fail(t, "Arguments must be maps", msgAndArgs...)
+	}
+
+	expectedMap := reflect.ValueOf(expected)
+	actualMap := reflect.ValueOf(actual)
+
+	if expectedMap.Len() != actualMap.Len() {
+		return Fail(t, "Arguments must have the same number of keys", msgAndArgs...)
+	}
+
+	for _, k := range expectedMap.MapKeys() {
+		ev := expectedMap.MapIndex(k)
+		av := actualMap.MapIndex(k)
+
+		if !ev.IsValid() {
+			return Fail(t, fmt.Sprintf("missing key %q in expected map", k), msgAndArgs...)
+		}
+
+		if !av.IsValid() {
+			return Fail(t, fmt.Sprintf("missing key %q in actual map", k), msgAndArgs...)
+		}
+
+		if !InDelta(
+			t,
+			ev.Interface(),
+			av.Interface(),
+			delta,
+			msgAndArgs...,
+		) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func calcRelativeError(expected, actual interface{}) (float64, error) {
+	af, aok := toFloat(expected)
+	if !aok {
+		return 0, fmt.Errorf("expected value %q cannot be converted to float", expected)
+	}
+	if af == 0 {
+		return 0, fmt.Errorf("expected value must have a value other than zero to calculate the relative error")
+	}
+	bf, bok := toFloat(actual)
+	if !bok {
+		return 0, fmt.Errorf("actual value %q cannot be converted to float", actual)
+	}
+
+	return math.Abs(af-bf) / math.Abs(af), nil
+}
+
+// InEpsilon asserts that expected and actual have a relative error less than epsilon
+func InEpsilon(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	actualEpsilon, err := calcRelativeError(expected, actual)
+	if err != nil {
+		return Fail(t, err.Error(), msgAndArgs...)
+	}
+	if actualEpsilon > epsilon {
+		return Fail(t, fmt.Sprintf("Relative error is too high: %#v (expected)\n"+
+			"        < %#v (actual)", epsilon, actualEpsilon), msgAndArgs...)
+	}
+
+	return true
+}
+
+// InEpsilonSlice is the same as InEpsilon, except it compares each value from two slices.
+func InEpsilonSlice(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if expected == nil || actual == nil ||
+		reflect.TypeOf(actual).Kind() != reflect.Slice ||
+		reflect.TypeOf(expected).Kind() != reflect.Slice {
+		return Fail(t, fmt.Sprintf("Parameters must be slice"), msgAndArgs...)
+	}
+
+	actualSlice := reflect.ValueOf(actual)
+	expectedSlice := reflect.ValueOf(expected)
+
+	for i := 0; i < actualSlice.Len(); i++ {
+		result := InEpsilon(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), epsilon)
+		if !result {
+			return result
+		}
+	}
+
+	return true
+}
+
+/*
+	Errors
+*/
+
+// NoError asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.NoError(t, err) {
+//	   assert.Equal(t, expectedObj, actualObj)
+//   }
+func NoError(t TestingT, err error, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if err != nil {
+		return Fail(t, fmt.Sprintf("Received unexpected error:\n%+v", err), msgAndArgs...)
+	}
+
+	return true
+}
+
+// Error asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.Error(t, err) {
+//	   assert.Equal(t, expectedError, err)
+//   }
+func Error(t TestingT, err error, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	if err == nil {
+		return Fail(t, "An error is expected but got nil.", msgAndArgs...)
+	}
+
+	return true
+}
+
+// EqualError asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   assert.EqualError(t, err,  expectedErrorString)
+func EqualError(t TestingT, theError error, errString string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if !Error(t, theError, msgAndArgs...) {
+		return false
+	}
+	expected := errString
+	actual := theError.Error()
+	// don't need to use deep equals here, we know they are both strings
+	if expected != actual {
+		return Fail(t, fmt.Sprintf("Error message not equal:\n"+
+			"expected: %q\n"+
+			"actual  : %q", expected, actual), msgAndArgs...)
+	}
+	return true
+}
+
+// matchRegexp return true if a specified regexp matches a string.
+func matchRegexp(rx interface{}, str interface{}) bool {
+
+	var r *regexp.Regexp
+	if rr, ok := rx.(*regexp.Regexp); ok {
+		r = rr
+	} else {
+		r = regexp.MustCompile(fmt.Sprint(rx))
+	}
+
+	return (r.FindStringIndex(fmt.Sprint(str)) != nil)
+
+}
+
+// Regexp asserts that a specified regexp matches a string.
+//
+//  assert.Regexp(t, regexp.MustCompile("start"), "it's starting")
+//  assert.Regexp(t, "start...$", "it's not starting")
+func Regexp(t TestingT, rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	match := matchRegexp(rx, str)
+
+	if !match {
+		Fail(t, fmt.Sprintf("Expect \"%v\" to match \"%v\"", str, rx), msgAndArgs...)
+	}
+
+	return match
+}
+
+// NotRegexp asserts that a specified regexp does not match a string.
+//
+//  assert.NotRegexp(t, regexp.MustCompile("starts"), "it's starting")
+//  assert.NotRegexp(t, "^start", "it's not starting")
+func NotRegexp(t TestingT, rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	match := matchRegexp(rx, str)
+
+	if match {
+		Fail(t, fmt.Sprintf("Expect \"%v\" to NOT match \"%v\"", str, rx), msgAndArgs...)
+	}
+
+	return !match
+
+}
+
+// Zero asserts that i is the zero value for its type.
+func Zero(t TestingT, i interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if i != nil && !reflect.DeepEqual(i, reflect.Zero(reflect.TypeOf(i)).Interface()) {
+		return Fail(t, fmt.Sprintf("Should be zero, but was %v", i), msgAndArgs...)
+	}
+	return true
+}
+
+// NotZero asserts that i is not the zero value for its type.
+func NotZero(t TestingT, i interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	if i == nil || reflect.DeepEqual(i, reflect.Zero(reflect.TypeOf(i)).Interface()) {
+		return Fail(t, fmt.Sprintf("Should not be zero, but was %v", i), msgAndArgs...)
+	}
+	return true
+}
+
+// FileExists checks whether a file exists in the given path. It also fails if the path points to a directory or there is an error when trying to check the file.
+func FileExists(t TestingT, path string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	info, err := os.Lstat(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Fail(t, fmt.Sprintf("unable to find file %q", path), msgAndArgs...)
+		}
+		return Fail(t, fmt.Sprintf("error when running os.Lstat(%q): %s", path, err), msgAndArgs...)
+	}
+	if info.IsDir() {
+		return Fail(t, fmt.Sprintf("%q is a directory", path), msgAndArgs...)
+	}
+	return true
+}
+
+// DirExists checks whether a directory exists in the given path. It also fails if the path is a file rather a directory or there is an error checking whether it exists.
+func DirExists(t TestingT, path string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	info, err := os.Lstat(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Fail(t, fmt.Sprintf("unable to find file %q", path), msgAndArgs...)
+		}
+		return Fail(t, fmt.Sprintf("error when running os.Lstat(%q): %s", path, err), msgAndArgs...)
+	}
+	if !info.IsDir() {
+		return Fail(t, fmt.Sprintf("%q is a file", path), msgAndArgs...)
+	}
+	return true
+}
+
+// JSONEq asserts that two JSON strings are equivalent.
+//
+//  assert.JSONEq(t, `{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`)
+func JSONEq(t TestingT, expected string, actual string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	var expectedJSONAsInterface, actualJSONAsInterface interface{}
+
+	if err := json.Unmarshal([]byte(expected), &expectedJSONAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Expected value ('%s') is not valid json.\nJSON parsing error: '%s'", expected, err.Error()), msgAndArgs...)
+	}
+
+	if err := json.Unmarshal([]byte(actual), &actualJSONAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Input ('%s') needs to be valid json.\nJSON parsing error: '%s'", actual, err.Error()), msgAndArgs...)
+	}
+
+	return Equal(t, expectedJSONAsInterface, actualJSONAsInterface, msgAndArgs...)
+}
+
+// YAMLEq asserts that two YAML strings are equivalent.
+func YAMLEq(t TestingT, expected string, actual string, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	var expectedYAMLAsInterface, actualYAMLAsInterface interface{}
+
+	if err := yaml.Unmarshal([]byte(expected), &expectedYAMLAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Expected value ('%s') is not valid yaml.\nYAML parsing error: '%s'", expected, err.Error()), msgAndArgs...)
+	}
+
+	if err := yaml.Unmarshal([]byte(actual), &actualYAMLAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Input ('%s') needs to be valid yaml.\nYAML error: '%s'", actual, err.Error()), msgAndArgs...)
+	}
+
+	return Equal(t, expectedYAMLAsInterface, actualYAMLAsInterface, msgAndArgs...)
+}
+
+func typeAndKind(v interface{}) (reflect.Type, reflect.Kind) {
+	t := reflect.TypeOf(v)
+	k := t.Kind()
+
+	if k == reflect.Ptr {
+		t = t.Elem()
+		k = t.Kind()
+	}
+	return t, k
+}
+
+// diff returns a diff of both values as long as both are of the same type and
+// are a struct, map, slice, array or string. Otherwise it returns an empty string.
+func diff(expected interface{}, actual interface{}) string {
+	if expected == nil || actual == nil {
+		return ""
+	}
+
+	et, ek := typeAndKind(expected)
+	at, _ := typeAndKind(actual)
+
+	if et != at {
+		return ""
+	}
+
+	if ek != reflect.Struct && ek != reflect.Map && ek != reflect.Slice && ek != reflect.Array && ek != reflect.String {
+		return ""
+	}
+
+	var e, a string
+	if et != reflect.TypeOf("") {
+		e = spewConfig.Sdump(expected)
+		a = spewConfig.Sdump(actual)
+	} else {
+		e = reflect.ValueOf(expected).String()
+		a = reflect.ValueOf(actual).String()
+	}
+
+	diff, _ := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
+		A:        difflib.SplitLines(e),
+		B:        difflib.SplitLines(a),
+		FromFile: "Expected",
+		FromDate: "",
+		ToFile:   "Actual",
+		ToDate:   "",
+		Context:  1,
+	})
+
+	return "\n\nDiff:\n" + diff
+}
+
+// validateEqualArgs checks whether provided arguments can be safely used in the
+// Equal/NotEqual functions.
+func validateEqualArgs(expected, actual interface{}) error {
+	if isFunction(expected) || isFunction(actual) {
+		return errors.New("cannot take func type as argument")
+	}
+	return nil
+}
+
+func isFunction(arg interface{}) bool {
+	if arg == nil {
+		return false
+	}
+	return reflect.TypeOf(arg).Kind() == reflect.Func
+}
+
+var spewConfig = spew.ConfigState{
+	Indent:                  " ",
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+	SortKeys:                true,
+}
+
+type tHelper interface {
+	Helper()
+}
+
+// Eventually asserts that given condition will be met in waitFor time,
+// periodically checking target function each tick.
+//
+//    assert.Eventually(t, func() bool { return true; }, time.Second, 10*time.Millisecond)
+func Eventually(t TestingT, condition func() bool, waitFor time.Duration, tick time.Duration, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+
+	timer := time.NewTimer(waitFor)
+	ticker := time.NewTicker(tick)
+	checkPassed := make(chan bool)
+	defer timer.Stop()
+	defer ticker.Stop()
+	defer close(checkPassed)
+	for {
+		select {
+		case <-timer.C:
+			return Fail(t, "Condition never satisfied", msgAndArgs...)
+		case result := <-checkPassed:
+			if result {
+				return true
+			}
+		case <-ticker.C:
+			go func() {
+				checkPassed <- condition()
+			}()
+		}
+	}
+}
diff --git a/vendor/github.com/stretchr/testify/assert/doc.go b/vendor/github.com/stretchr/testify/assert/doc.go
new file mode 100644
index 0000000..c9dccc4
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/doc.go
@@ -0,0 +1,45 @@
+// Package assert provides a set of comprehensive testing tools for use with the normal Go testing system.
+//
+// Example Usage
+//
+// The following is a complete example using assert in a standard test function:
+//    import (
+//      "testing"
+//      "github.com/stretchr/testify/assert"
+//    )
+//
+//    func TestSomething(t *testing.T) {
+//
+//      var a string = "Hello"
+//      var b string = "Hello"
+//
+//      assert.Equal(t, a, b, "The two words should be the same.")
+//
+//    }
+//
+// if you assert many times, use the format below:
+//
+//    import (
+//      "testing"
+//      "github.com/stretchr/testify/assert"
+//    )
+//
+//    func TestSomething(t *testing.T) {
+//      assert := assert.New(t)
+//
+//      var a string = "Hello"
+//      var b string = "Hello"
+//
+//      assert.Equal(a, b, "The two words should be the same.")
+//    }
+//
+// Assertions
+//
+// Assertions allow you to easily write test code, and are global funcs in the `assert` package.
+// All assertion functions take, as the first argument, the `*testing.T` object provided by the
+// testing framework. This allows the assertion funcs to write the failings and other details to
+// the correct place.
+//
+// Every assertion function also takes an optional string message as the final argument,
+// allowing custom error messages to be appended to the message the assertion method outputs.
+package assert
diff --git a/vendor/github.com/stretchr/testify/assert/errors.go b/vendor/github.com/stretchr/testify/assert/errors.go
new file mode 100644
index 0000000..ac9dc9d
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/errors.go
@@ -0,0 +1,10 @@
+package assert
+
+import (
+	"errors"
+)
+
+// AnError is an error instance useful for testing.  If the code does not care
+// about error specifics, and only needs to return the error for example, this
+// error should be used to make the test code more readable.
+var AnError = errors.New("assert.AnError general error for testing")
diff --git a/vendor/github.com/stretchr/testify/assert/forward_assertions.go b/vendor/github.com/stretchr/testify/assert/forward_assertions.go
new file mode 100644
index 0000000..9ad5685
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/forward_assertions.go
@@ -0,0 +1,16 @@
+package assert
+
+// Assertions provides assertion methods around the
+// TestingT interface.
+type Assertions struct {
+	t TestingT
+}
+
+// New makes a new Assertions object for the specified TestingT.
+func New(t TestingT) *Assertions {
+	return &Assertions{
+		t: t,
+	}
+}
+
+//go:generate go run ../_codegen/main.go -output-package=assert -template=assertion_forward.go.tmpl -include-format-funcs
diff --git a/vendor/github.com/stretchr/testify/assert/http_assertions.go b/vendor/github.com/stretchr/testify/assert/http_assertions.go
new file mode 100644
index 0000000..df46fa7
--- /dev/null
+++ b/vendor/github.com/stretchr/testify/assert/http_assertions.go
@@ -0,0 +1,143 @@
+package assert
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+)
+
+// httpCode is a helper that returns HTTP code of the response. It returns -1 and
+// an error if building a new request fails.
+func httpCode(handler http.HandlerFunc, method, url string, values url.Values) (int, error) {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest(method, url, nil)
+	if err != nil {
+		return -1, err
+	}
+	req.URL.RawQuery = values.Encode()
+	handler(w, req)
+	return w.Code, nil
+}
+
+// HTTPSuccess asserts that a specified handler returns a success status code.
+//
+//  assert.HTTPSuccess(t, myHandler, "POST", "http://www.google.com", nil)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPSuccess(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	code, err := httpCode(handler, method, url, values)
+	if err != nil {
+		Fail(t, fmt.Sprintf("Failed to build test request, got error: %s", err))
+		return false
+	}
+
+	isSuccessCode := code >= http.StatusOK && code <= http.StatusPartialContent
+	if !isSuccessCode {
+		Fail(t, fmt.Sprintf("Expected HTTP success status code for %q but received %d", url+"?"+values.Encode(), code))
+	}
+
+	return isSuccessCode
+}
+
+// HTTPRedirect asserts that a specified handler returns a redirect status code.
+//
+//  assert.HTTPRedirect(t, myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPRedirect(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	code, err := httpCode(handler, method, url, values)
+	if err != nil {
+		Fail(t, fmt.Sprintf("Failed to build test request, got error: %s", err))
+		return false
+	}
+
+	isRedirectCode := code >= http.StatusMultipleChoices && code <= http.StatusTemporaryRedirect
+	if !isRedirectCode {
+		Fail(t, fmt.Sprintf("Expected HTTP redirect status code for %q but received %d", url+"?"+values.Encode(), code))
+	}
+
+	return isRedirectCode
+}
+
+// HTTPError asserts that a specified handler returns an error status code.
+//
+//  assert.HTTPError(t, myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPError(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	code, err := httpCode(handler, method, url, values)
+	if err != nil {
+		Fail(t, fmt.Sprintf("Failed to build test request, got error: %s", err))
+		return false
+	}
+
+	isErrorCode := code >= http.StatusBadRequest
+	if !isErrorCode {
+		Fail(t, fmt.Sprintf("Expected HTTP error status code for %q but received %d", url+"?"+values.Encode(), code))
+	}
+
+	return isErrorCode
+}
+
+// HTTPBody is a helper that returns HTTP body of the response. It returns
+// empty string if building a new request fails.
+func HTTPBody(handler http.HandlerFunc, method, url string, values url.Values) string {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest(method, url+"?"+values.Encode(), nil)
+	if err != nil {
+		return ""
+	}
+	handler(w, req)
+	return w.Body.String()
+}
+
+// HTTPBodyContains asserts that a specified handler returns a
+// body that contains a string.
+//
+//  assert.HTTPBodyContains(t, myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyContains(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	body := HTTPBody(handler, method, url, values)
+
+	contains := strings.Contains(body, fmt.Sprint(str))
+	if !contains {
+		Fail(t, fmt.Sprintf("Expected response body for \"%s\" to contain \"%s\" but found \"%s\"", url+"?"+values.Encode(), str, body))
+	}
+
+	return contains
+}
+
+// HTTPBodyNotContains asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  assert.HTTPBodyNotContains(t, myHandler, "GET", "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyNotContains(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, str interface{}, msgAndArgs ...interface{}) bool {
+	if h, ok := t.(tHelper); ok {
+		h.Helper()
+	}
+	body := HTTPBody(handler, method, url, values)
+
+	contains := strings.Contains(body, fmt.Sprint(str))
+	if contains {
+		Fail(t, fmt.Sprintf("Expected response body for \"%s\" to NOT contain \"%s\" but found \"%s\"", url+"?"+values.Encode(), str, body))
+	}
+
+	return !contains
+}