diff --git a/vendor/go.uber.org/zap/zapcore/memory_encoder.go b/vendor/go.uber.org/zap/zapcore/memory_encoder.go
new file mode 100644
index 0000000..dfead08
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/memory_encoder.go
@@ -0,0 +1,179 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// 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.
+
+package zapcore
+
+import "time"
+
+// MapObjectEncoder is an ObjectEncoder backed by a simple
+// map[string]interface{}. It's not fast enough for production use, but it's
+// helpful in tests.
+type MapObjectEncoder struct {
+	// Fields contains the entire encoded log context.
+	Fields map[string]interface{}
+	// cur is a pointer to the namespace we're currently writing to.
+	cur map[string]interface{}
+}
+
+// NewMapObjectEncoder creates a new map-backed ObjectEncoder.
+func NewMapObjectEncoder() *MapObjectEncoder {
+	m := make(map[string]interface{})
+	return &MapObjectEncoder{
+		Fields: m,
+		cur:    m,
+	}
+}
+
+// AddArray implements ObjectEncoder.
+func (m *MapObjectEncoder) AddArray(key string, v ArrayMarshaler) error {
+	arr := &sliceArrayEncoder{elems: make([]interface{}, 0)}
+	err := v.MarshalLogArray(arr)
+	m.cur[key] = arr.elems
+	return err
+}
+
+// AddObject implements ObjectEncoder.
+func (m *MapObjectEncoder) AddObject(k string, v ObjectMarshaler) error {
+	newMap := NewMapObjectEncoder()
+	m.cur[k] = newMap.Fields
+	return v.MarshalLogObject(newMap)
+}
+
+// AddBinary implements ObjectEncoder.
+func (m *MapObjectEncoder) AddBinary(k string, v []byte) { m.cur[k] = v }
+
+// AddByteString implements ObjectEncoder.
+func (m *MapObjectEncoder) AddByteString(k string, v []byte) { m.cur[k] = string(v) }
+
+// AddBool implements ObjectEncoder.
+func (m *MapObjectEncoder) AddBool(k string, v bool) { m.cur[k] = v }
+
+// AddDuration implements ObjectEncoder.
+func (m MapObjectEncoder) AddDuration(k string, v time.Duration) { m.cur[k] = v }
+
+// AddComplex128 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddComplex128(k string, v complex128) { m.cur[k] = v }
+
+// AddComplex64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddComplex64(k string, v complex64) { m.cur[k] = v }
+
+// AddFloat64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddFloat64(k string, v float64) { m.cur[k] = v }
+
+// AddFloat32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddFloat32(k string, v float32) { m.cur[k] = v }
+
+// AddInt implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt(k string, v int) { m.cur[k] = v }
+
+// AddInt64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt64(k string, v int64) { m.cur[k] = v }
+
+// AddInt32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt32(k string, v int32) { m.cur[k] = v }
+
+// AddInt16 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt16(k string, v int16) { m.cur[k] = v }
+
+// AddInt8 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt8(k string, v int8) { m.cur[k] = v }
+
+// AddString implements ObjectEncoder.
+func (m *MapObjectEncoder) AddString(k string, v string) { m.cur[k] = v }
+
+// AddTime implements ObjectEncoder.
+func (m MapObjectEncoder) AddTime(k string, v time.Time) { m.cur[k] = v }
+
+// AddUint implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint(k string, v uint) { m.cur[k] = v }
+
+// AddUint64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint64(k string, v uint64) { m.cur[k] = v }
+
+// AddUint32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint32(k string, v uint32) { m.cur[k] = v }
+
+// AddUint16 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint16(k string, v uint16) { m.cur[k] = v }
+
+// AddUint8 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint8(k string, v uint8) { m.cur[k] = v }
+
+// AddUintptr implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUintptr(k string, v uintptr) { m.cur[k] = v }
+
+// AddReflected implements ObjectEncoder.
+func (m *MapObjectEncoder) AddReflected(k string, v interface{}) error {
+	m.cur[k] = v
+	return nil
+}
+
+// OpenNamespace implements ObjectEncoder.
+func (m *MapObjectEncoder) OpenNamespace(k string) {
+	ns := make(map[string]interface{})
+	m.cur[k] = ns
+	m.cur = ns
+}
+
+// sliceArrayEncoder is an ArrayEncoder backed by a simple []interface{}. Like
+// the MapObjectEncoder, it's not designed for production use.
+type sliceArrayEncoder struct {
+	elems []interface{}
+}
+
+func (s *sliceArrayEncoder) AppendArray(v ArrayMarshaler) error {
+	enc := &sliceArrayEncoder{}
+	err := v.MarshalLogArray(enc)
+	s.elems = append(s.elems, enc.elems)
+	return err
+}
+
+func (s *sliceArrayEncoder) AppendObject(v ObjectMarshaler) error {
+	m := NewMapObjectEncoder()
+	err := v.MarshalLogObject(m)
+	s.elems = append(s.elems, m.Fields)
+	return err
+}
+
+func (s *sliceArrayEncoder) AppendReflected(v interface{}) error {
+	s.elems = append(s.elems, v)
+	return nil
+}
+
+func (s *sliceArrayEncoder) AppendBool(v bool)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendByteString(v []byte)      { s.elems = append(s.elems, string(v)) }
+func (s *sliceArrayEncoder) AppendComplex128(v complex128)  { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendComplex64(v complex64)    { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendDuration(v time.Duration) { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendFloat64(v float64)        { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendFloat32(v float32)        { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt(v int)                { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt64(v int64)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt32(v int32)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt16(v int16)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt8(v int8)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendString(v string)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendTime(v time.Time)         { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint(v uint)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint64(v uint64)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint32(v uint32)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint16(v uint16)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint8(v uint8)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUintptr(v uintptr)        { s.elems = append(s.elems, v) }