diff --git a/vendor/github.com/davecgh/go-spew/spew/common.go b/vendor/github.com/davecgh/go-spew/spew/common.go
new file mode 100644
index 0000000..1be8ce9
--- /dev/null
+++ b/vendor/github.com/davecgh/go-spew/spew/common.go
@@ -0,0 +1,341 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"sort"
+	"strconv"
+)
+
+// Some constants in the form of bytes to avoid string overhead.  This mirrors
+// the technique used in the fmt package.
+var (
+	panicBytes            = []byte("(PANIC=")
+	plusBytes             = []byte("+")
+	iBytes                = []byte("i")
+	trueBytes             = []byte("true")
+	falseBytes            = []byte("false")
+	interfaceBytes        = []byte("(interface {})")
+	commaNewlineBytes     = []byte(",\n")
+	newlineBytes          = []byte("\n")
+	openBraceBytes        = []byte("{")
+	openBraceNewlineBytes = []byte("{\n")
+	closeBraceBytes       = []byte("}")
+	asteriskBytes         = []byte("*")
+	colonBytes            = []byte(":")
+	colonSpaceBytes       = []byte(": ")
+	openParenBytes        = []byte("(")
+	closeParenBytes       = []byte(")")
+	spaceBytes            = []byte(" ")
+	pointerChainBytes     = []byte("->")
+	nilAngleBytes         = []byte("<nil>")
+	maxNewlineBytes       = []byte("<max depth reached>\n")
+	maxShortBytes         = []byte("<max>")
+	circularBytes         = []byte("<already shown>")
+	circularShortBytes    = []byte("<shown>")
+	invalidAngleBytes     = []byte("<invalid>")
+	openBracketBytes      = []byte("[")
+	closeBracketBytes     = []byte("]")
+	percentBytes          = []byte("%")
+	precisionBytes        = []byte(".")
+	openAngleBytes        = []byte("<")
+	closeAngleBytes       = []byte(">")
+	openMapBytes          = []byte("map[")
+	closeMapBytes         = []byte("]")
+	lenEqualsBytes        = []byte("len=")
+	capEqualsBytes        = []byte("cap=")
+)
+
+// hexDigits is used to map a decimal value to a hex digit.
+var hexDigits = "0123456789abcdef"
+
+// catchPanic handles any panics that might occur during the handleMethods
+// calls.
+func catchPanic(w io.Writer, v reflect.Value) {
+	if err := recover(); err != nil {
+		w.Write(panicBytes)
+		fmt.Fprintf(w, "%v", err)
+		w.Write(closeParenBytes)
+	}
+}
+
+// handleMethods attempts to call the Error and String methods on the underlying
+// type the passed reflect.Value represents and outputes the result to Writer w.
+//
+// It handles panics in any called methods by catching and displaying the error
+// as the formatted value.
+func handleMethods(cs *ConfigState, w io.Writer, v reflect.Value) (handled bool) {
+	// We need an interface to check if the type implements the error or
+	// Stringer interface.  However, the reflect package won't give us an
+	// interface on certain things like unexported struct fields in order
+	// to enforce visibility rules.  We use unsafe, when it's available,
+	// to bypass these restrictions since this package does not mutate the
+	// values.
+	if !v.CanInterface() {
+		if UnsafeDisabled {
+			return false
+		}
+
+		v = unsafeReflectValue(v)
+	}
+
+	// Choose whether or not to do error and Stringer interface lookups against
+	// the base type or a pointer to the base type depending on settings.
+	// Technically calling one of these methods with a pointer receiver can
+	// mutate the value, however, types which choose to satisify an error or
+	// Stringer interface with a pointer receiver should not be mutating their
+	// state inside these interface methods.
+	if !cs.DisablePointerMethods && !UnsafeDisabled && !v.CanAddr() {
+		v = unsafeReflectValue(v)
+	}
+	if v.CanAddr() {
+		v = v.Addr()
+	}
+
+	// Is it an error or Stringer?
+	switch iface := v.Interface().(type) {
+	case error:
+		defer catchPanic(w, v)
+		if cs.ContinueOnMethod {
+			w.Write(openParenBytes)
+			w.Write([]byte(iface.Error()))
+			w.Write(closeParenBytes)
+			w.Write(spaceBytes)
+			return false
+		}
+
+		w.Write([]byte(iface.Error()))
+		return true
+
+	case fmt.Stringer:
+		defer catchPanic(w, v)
+		if cs.ContinueOnMethod {
+			w.Write(openParenBytes)
+			w.Write([]byte(iface.String()))
+			w.Write(closeParenBytes)
+			w.Write(spaceBytes)
+			return false
+		}
+		w.Write([]byte(iface.String()))
+		return true
+	}
+	return false
+}
+
+// printBool outputs a boolean value as true or false to Writer w.
+func printBool(w io.Writer, val bool) {
+	if val {
+		w.Write(trueBytes)
+	} else {
+		w.Write(falseBytes)
+	}
+}
+
+// printInt outputs a signed integer value to Writer w.
+func printInt(w io.Writer, val int64, base int) {
+	w.Write([]byte(strconv.FormatInt(val, base)))
+}
+
+// printUint outputs an unsigned integer value to Writer w.
+func printUint(w io.Writer, val uint64, base int) {
+	w.Write([]byte(strconv.FormatUint(val, base)))
+}
+
+// printFloat outputs a floating point value using the specified precision,
+// which is expected to be 32 or 64bit, to Writer w.
+func printFloat(w io.Writer, val float64, precision int) {
+	w.Write([]byte(strconv.FormatFloat(val, 'g', -1, precision)))
+}
+
+// printComplex outputs a complex value using the specified float precision
+// for the real and imaginary parts to Writer w.
+func printComplex(w io.Writer, c complex128, floatPrecision int) {
+	r := real(c)
+	w.Write(openParenBytes)
+	w.Write([]byte(strconv.FormatFloat(r, 'g', -1, floatPrecision)))
+	i := imag(c)
+	if i >= 0 {
+		w.Write(plusBytes)
+	}
+	w.Write([]byte(strconv.FormatFloat(i, 'g', -1, floatPrecision)))
+	w.Write(iBytes)
+	w.Write(closeParenBytes)
+}
+
+// printHexPtr outputs a uintptr formatted as hexadecimal with a leading '0x'
+// prefix to Writer w.
+func printHexPtr(w io.Writer, p uintptr) {
+	// Null pointer.
+	num := uint64(p)
+	if num == 0 {
+		w.Write(nilAngleBytes)
+		return
+	}
+
+	// Max uint64 is 16 bytes in hex + 2 bytes for '0x' prefix
+	buf := make([]byte, 18)
+
+	// It's simpler to construct the hex string right to left.
+	base := uint64(16)
+	i := len(buf) - 1
+	for num >= base {
+		buf[i] = hexDigits[num%base]
+		num /= base
+		i--
+	}
+	buf[i] = hexDigits[num]
+
+	// Add '0x' prefix.
+	i--
+	buf[i] = 'x'
+	i--
+	buf[i] = '0'
+
+	// Strip unused leading bytes.
+	buf = buf[i:]
+	w.Write(buf)
+}
+
+// valuesSorter implements sort.Interface to allow a slice of reflect.Value
+// elements to be sorted.
+type valuesSorter struct {
+	values  []reflect.Value
+	strings []string // either nil or same len and values
+	cs      *ConfigState
+}
+
+// newValuesSorter initializes a valuesSorter instance, which holds a set of
+// surrogate keys on which the data should be sorted.  It uses flags in
+// ConfigState to decide if and how to populate those surrogate keys.
+func newValuesSorter(values []reflect.Value, cs *ConfigState) sort.Interface {
+	vs := &valuesSorter{values: values, cs: cs}
+	if canSortSimply(vs.values[0].Kind()) {
+		return vs
+	}
+	if !cs.DisableMethods {
+		vs.strings = make([]string, len(values))
+		for i := range vs.values {
+			b := bytes.Buffer{}
+			if !handleMethods(cs, &b, vs.values[i]) {
+				vs.strings = nil
+				break
+			}
+			vs.strings[i] = b.String()
+		}
+	}
+	if vs.strings == nil && cs.SpewKeys {
+		vs.strings = make([]string, len(values))
+		for i := range vs.values {
+			vs.strings[i] = Sprintf("%#v", vs.values[i].Interface())
+		}
+	}
+	return vs
+}
+
+// canSortSimply tests whether a reflect.Kind is a primitive that can be sorted
+// directly, or whether it should be considered for sorting by surrogate keys
+// (if the ConfigState allows it).
+func canSortSimply(kind reflect.Kind) bool {
+	// This switch parallels valueSortLess, except for the default case.
+	switch kind {
+	case reflect.Bool:
+		return true
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return true
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		return true
+	case reflect.Float32, reflect.Float64:
+		return true
+	case reflect.String:
+		return true
+	case reflect.Uintptr:
+		return true
+	case reflect.Array:
+		return true
+	}
+	return false
+}
+
+// Len returns the number of values in the slice.  It is part of the
+// sort.Interface implementation.
+func (s *valuesSorter) Len() int {
+	return len(s.values)
+}
+
+// Swap swaps the values at the passed indices.  It is part of the
+// sort.Interface implementation.
+func (s *valuesSorter) Swap(i, j int) {
+	s.values[i], s.values[j] = s.values[j], s.values[i]
+	if s.strings != nil {
+		s.strings[i], s.strings[j] = s.strings[j], s.strings[i]
+	}
+}
+
+// valueSortLess returns whether the first value should sort before the second
+// value.  It is used by valueSorter.Less as part of the sort.Interface
+// implementation.
+func valueSortLess(a, b reflect.Value) bool {
+	switch a.Kind() {
+	case reflect.Bool:
+		return !a.Bool() && b.Bool()
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return a.Int() < b.Int()
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		return a.Uint() < b.Uint()
+	case reflect.Float32, reflect.Float64:
+		return a.Float() < b.Float()
+	case reflect.String:
+		return a.String() < b.String()
+	case reflect.Uintptr:
+		return a.Uint() < b.Uint()
+	case reflect.Array:
+		// Compare the contents of both arrays.
+		l := a.Len()
+		for i := 0; i < l; i++ {
+			av := a.Index(i)
+			bv := b.Index(i)
+			if av.Interface() == bv.Interface() {
+				continue
+			}
+			return valueSortLess(av, bv)
+		}
+	}
+	return a.String() < b.String()
+}
+
+// Less returns whether the value at index i should sort before the
+// value at index j.  It is part of the sort.Interface implementation.
+func (s *valuesSorter) Less(i, j int) bool {
+	if s.strings == nil {
+		return valueSortLess(s.values[i], s.values[j])
+	}
+	return s.strings[i] < s.strings[j]
+}
+
+// sortValues is a sort function that handles both native types and any type that
+// can be converted to error or Stringer.  Other inputs are sorted according to
+// their Value.String() value to ensure display stability.
+func sortValues(values []reflect.Value, cs *ConfigState) {
+	if len(values) == 0 {
+		return
+	}
+	sort.Sort(newValuesSorter(values, cs))
+}