diff --git a/vendor/github.com/rs/zerolog/context.go b/vendor/github.com/rs/zerolog/context.go
new file mode 100644
index 0000000..b843179
--- /dev/null
+++ b/vendor/github.com/rs/zerolog/context.go
@@ -0,0 +1,381 @@
+package zerolog
+
+import (
+	"io/ioutil"
+	"net"
+	"time"
+)
+
+// Context configures a new sub-logger with contextual fields.
+type Context struct {
+	l Logger
+}
+
+// Logger returns the logger with the context previously set.
+func (c Context) Logger() Logger {
+	return c.l
+}
+
+// Fields is a helper function to use a map to set fields using type assertion.
+func (c Context) Fields(fields map[string]interface{}) Context {
+	c.l.context = appendFields(c.l.context, fields)
+	return c
+}
+
+// Dict adds the field key with the dict to the logger context.
+func (c Context) Dict(key string, dict *Event) Context {
+	dict.buf = enc.AppendEndMarker(dict.buf)
+	c.l.context = append(enc.AppendKey(c.l.context, key), dict.buf...)
+	putEvent(dict)
+	return c
+}
+
+// Array adds the field key with an array to the event context.
+// Use zerolog.Arr() to create the array or pass a type that
+// implement the LogArrayMarshaler interface.
+func (c Context) Array(key string, arr LogArrayMarshaler) Context {
+	c.l.context = enc.AppendKey(c.l.context, key)
+	if arr, ok := arr.(*Array); ok {
+		c.l.context = arr.write(c.l.context)
+		return c
+	}
+	var a *Array
+	if aa, ok := arr.(*Array); ok {
+		a = aa
+	} else {
+		a = Arr()
+		arr.MarshalZerologArray(a)
+	}
+	c.l.context = a.write(c.l.context)
+	return c
+}
+
+// Object marshals an object that implement the LogObjectMarshaler interface.
+func (c Context) Object(key string, obj LogObjectMarshaler) Context {
+	e := newEvent(levelWriterAdapter{ioutil.Discard}, 0)
+	e.Object(key, obj)
+	c.l.context = enc.AppendObjectData(c.l.context, e.buf)
+	putEvent(e)
+	return c
+}
+
+// EmbedObject marshals and Embeds an object that implement the LogObjectMarshaler interface.
+func (c Context) EmbedObject(obj LogObjectMarshaler) Context {
+	e := newEvent(levelWriterAdapter{ioutil.Discard}, 0)
+	e.EmbedObject(obj)
+	c.l.context = enc.AppendObjectData(c.l.context, e.buf)
+	putEvent(e)
+	return c
+}
+
+// Str adds the field key with val as a string to the logger context.
+func (c Context) Str(key, val string) Context {
+	c.l.context = enc.AppendString(enc.AppendKey(c.l.context, key), val)
+	return c
+}
+
+// Strs adds the field key with val as a string to the logger context.
+func (c Context) Strs(key string, vals []string) Context {
+	c.l.context = enc.AppendStrings(enc.AppendKey(c.l.context, key), vals)
+	return c
+}
+
+// Bytes adds the field key with val as a []byte to the logger context.
+func (c Context) Bytes(key string, val []byte) Context {
+	c.l.context = enc.AppendBytes(enc.AppendKey(c.l.context, key), val)
+	return c
+}
+
+// Hex adds the field key with val as a hex string to the logger context.
+func (c Context) Hex(key string, val []byte) Context {
+	c.l.context = enc.AppendHex(enc.AppendKey(c.l.context, key), val)
+	return c
+}
+
+// RawJSON adds already encoded JSON to context.
+//
+// No sanity check is performed on b; it must not contain carriage returns and
+// be valid JSON.
+func (c Context) RawJSON(key string, b []byte) Context {
+	c.l.context = appendJSON(enc.AppendKey(c.l.context, key), b)
+	return c
+}
+
+// AnErr adds the field key with serialized err to the logger context.
+func (c Context) AnErr(key string, err error) Context {
+	marshaled := ErrorMarshalFunc(err)
+	switch m := marshaled.(type) {
+	case nil:
+		return c
+	case LogObjectMarshaler:
+		return c.Object(key, m)
+	case error:
+		return c.Str(key, m.Error())
+	case string:
+		return c.Str(key, m)
+	default:
+		return c.Interface(key, m)
+	}
+}
+
+// Errs adds the field key with errs as an array of serialized errors to the
+// logger context.
+func (c Context) Errs(key string, errs []error) Context {
+	arr := Arr()
+	for _, err := range errs {
+		marshaled := ErrorMarshalFunc(err)
+		switch m := marshaled.(type) {
+		case LogObjectMarshaler:
+			arr = arr.Object(m)
+		case error:
+			arr = arr.Str(m.Error())
+		case string:
+			arr = arr.Str(m)
+		default:
+			arr = arr.Interface(m)
+		}
+	}
+
+	return c.Array(key, arr)
+}
+
+// Err adds the field "error" with serialized err to the logger context.
+func (c Context) Err(err error) Context {
+	return c.AnErr(ErrorFieldName, err)
+}
+
+// Bool adds the field key with val as a bool to the logger context.
+func (c Context) Bool(key string, b bool) Context {
+	c.l.context = enc.AppendBool(enc.AppendKey(c.l.context, key), b)
+	return c
+}
+
+// Bools adds the field key with val as a []bool to the logger context.
+func (c Context) Bools(key string, b []bool) Context {
+	c.l.context = enc.AppendBools(enc.AppendKey(c.l.context, key), b)
+	return c
+}
+
+// Int adds the field key with i as a int to the logger context.
+func (c Context) Int(key string, i int) Context {
+	c.l.context = enc.AppendInt(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Ints adds the field key with i as a []int to the logger context.
+func (c Context) Ints(key string, i []int) Context {
+	c.l.context = enc.AppendInts(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Int8 adds the field key with i as a int8 to the logger context.
+func (c Context) Int8(key string, i int8) Context {
+	c.l.context = enc.AppendInt8(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Ints8 adds the field key with i as a []int8 to the logger context.
+func (c Context) Ints8(key string, i []int8) Context {
+	c.l.context = enc.AppendInts8(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Int16 adds the field key with i as a int16 to the logger context.
+func (c Context) Int16(key string, i int16) Context {
+	c.l.context = enc.AppendInt16(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Ints16 adds the field key with i as a []int16 to the logger context.
+func (c Context) Ints16(key string, i []int16) Context {
+	c.l.context = enc.AppendInts16(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Int32 adds the field key with i as a int32 to the logger context.
+func (c Context) Int32(key string, i int32) Context {
+	c.l.context = enc.AppendInt32(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Ints32 adds the field key with i as a []int32 to the logger context.
+func (c Context) Ints32(key string, i []int32) Context {
+	c.l.context = enc.AppendInts32(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Int64 adds the field key with i as a int64 to the logger context.
+func (c Context) Int64(key string, i int64) Context {
+	c.l.context = enc.AppendInt64(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Ints64 adds the field key with i as a []int64 to the logger context.
+func (c Context) Ints64(key string, i []int64) Context {
+	c.l.context = enc.AppendInts64(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uint adds the field key with i as a uint to the logger context.
+func (c Context) Uint(key string, i uint) Context {
+	c.l.context = enc.AppendUint(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uints adds the field key with i as a []uint to the logger context.
+func (c Context) Uints(key string, i []uint) Context {
+	c.l.context = enc.AppendUints(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uint8 adds the field key with i as a uint8 to the logger context.
+func (c Context) Uint8(key string, i uint8) Context {
+	c.l.context = enc.AppendUint8(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uints8 adds the field key with i as a []uint8 to the logger context.
+func (c Context) Uints8(key string, i []uint8) Context {
+	c.l.context = enc.AppendUints8(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uint16 adds the field key with i as a uint16 to the logger context.
+func (c Context) Uint16(key string, i uint16) Context {
+	c.l.context = enc.AppendUint16(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uints16 adds the field key with i as a []uint16 to the logger context.
+func (c Context) Uints16(key string, i []uint16) Context {
+	c.l.context = enc.AppendUints16(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uint32 adds the field key with i as a uint32 to the logger context.
+func (c Context) Uint32(key string, i uint32) Context {
+	c.l.context = enc.AppendUint32(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uints32 adds the field key with i as a []uint32 to the logger context.
+func (c Context) Uints32(key string, i []uint32) Context {
+	c.l.context = enc.AppendUints32(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uint64 adds the field key with i as a uint64 to the logger context.
+func (c Context) Uint64(key string, i uint64) Context {
+	c.l.context = enc.AppendUint64(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Uints64 adds the field key with i as a []uint64 to the logger context.
+func (c Context) Uints64(key string, i []uint64) Context {
+	c.l.context = enc.AppendUints64(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+// Float32 adds the field key with f as a float32 to the logger context.
+func (c Context) Float32(key string, f float32) Context {
+	c.l.context = enc.AppendFloat32(enc.AppendKey(c.l.context, key), f)
+	return c
+}
+
+// Floats32 adds the field key with f as a []float32 to the logger context.
+func (c Context) Floats32(key string, f []float32) Context {
+	c.l.context = enc.AppendFloats32(enc.AppendKey(c.l.context, key), f)
+	return c
+}
+
+// Float64 adds the field key with f as a float64 to the logger context.
+func (c Context) Float64(key string, f float64) Context {
+	c.l.context = enc.AppendFloat64(enc.AppendKey(c.l.context, key), f)
+	return c
+}
+
+// Floats64 adds the field key with f as a []float64 to the logger context.
+func (c Context) Floats64(key string, f []float64) Context {
+	c.l.context = enc.AppendFloats64(enc.AppendKey(c.l.context, key), f)
+	return c
+}
+
+type timestampHook struct{}
+
+func (ts timestampHook) Run(e *Event, level Level, msg string) {
+	e.Timestamp()
+}
+
+var th = timestampHook{}
+
+// Timestamp adds the current local time as UNIX timestamp to the logger context with the "time" key.
+// To customize the key name, change zerolog.TimestampFieldName.
+//
+// NOTE: It won't dedupe the "time" key if the *Context has one already.
+func (c Context) Timestamp() Context {
+	c.l = c.l.Hook(th)
+	return c
+}
+
+// Time adds the field key with t formated as string using zerolog.TimeFieldFormat.
+func (c Context) Time(key string, t time.Time) Context {
+	c.l.context = enc.AppendTime(enc.AppendKey(c.l.context, key), t, TimeFieldFormat)
+	return c
+}
+
+// Times adds the field key with t formated as string using zerolog.TimeFieldFormat.
+func (c Context) Times(key string, t []time.Time) Context {
+	c.l.context = enc.AppendTimes(enc.AppendKey(c.l.context, key), t, TimeFieldFormat)
+	return c
+}
+
+// Dur adds the fields key with d divided by unit and stored as a float.
+func (c Context) Dur(key string, d time.Duration) Context {
+	c.l.context = enc.AppendDuration(enc.AppendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
+	return c
+}
+
+// Durs adds the fields key with d divided by unit and stored as a float.
+func (c Context) Durs(key string, d []time.Duration) Context {
+	c.l.context = enc.AppendDurations(enc.AppendKey(c.l.context, key), d, DurationFieldUnit, DurationFieldInteger)
+	return c
+}
+
+// Interface adds the field key with obj marshaled using reflection.
+func (c Context) Interface(key string, i interface{}) Context {
+	c.l.context = enc.AppendInterface(enc.AppendKey(c.l.context, key), i)
+	return c
+}
+
+type callerHook struct{}
+
+func (ch callerHook) Run(e *Event, level Level, msg string) {
+	// Three extra frames to skip (added by hook infra).
+	e.caller(CallerSkipFrameCount + 3)
+}
+
+var ch = callerHook{}
+
+// Caller adds the file:line of the caller with the zerolog.CallerFieldName key.
+func (c Context) Caller() Context {
+	c.l = c.l.Hook(ch)
+	return c
+}
+
+// IPAddr adds IPv4 or IPv6 Address to the context
+func (c Context) IPAddr(key string, ip net.IP) Context {
+	c.l.context = enc.AppendIPAddr(enc.AppendKey(c.l.context, key), ip)
+	return c
+}
+
+// IPPrefix adds IPv4 or IPv6 Prefix (address and mask) to the context
+func (c Context) IPPrefix(key string, pfx net.IPNet) Context {
+	c.l.context = enc.AppendIPPrefix(enc.AppendKey(c.l.context, key), pfx)
+	return c
+}
+
+// MACAddr adds MAC address to the context
+func (c Context) MACAddr(key string, ha net.HardwareAddr) Context {
+	c.l.context = enc.AppendMACAddr(enc.AppendKey(c.l.context, key), ha)
+	return c
+}