diff --git a/vendor/github.com/mongodb/mongo-go-driver/bson/marshal.go b/vendor/github.com/mongodb/mongo-go-driver/bson/marshal.go
new file mode 100644
index 0000000..398fb63
--- /dev/null
+++ b/vendor/github.com/mongodb/mongo-go-driver/bson/marshal.go
@@ -0,0 +1,156 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bson
+
+import (
+	"github.com/mongodb/mongo-go-driver/bson/bsoncodec"
+	"github.com/mongodb/mongo-go-driver/bson/bsonrw"
+	"github.com/mongodb/mongo-go-driver/bson/bsontype"
+)
+
+const defaultDstCap = 256
+
+var bvwPool = bsonrw.NewBSONValueWriterPool()
+var extjPool = bsonrw.NewExtJSONValueWriterPool()
+
+// Marshaler is an interface implemented by types that can marshal themselves
+// into a BSON document represented as bytes. The bytes returned must be a valid
+// BSON document if the error is nil.
+type Marshaler interface {
+	MarshalBSON() ([]byte, error)
+}
+
+// ValueMarshaler is an interface implemented by types that can marshal
+// themselves into a BSON value as bytes. The type must be the valid type for
+// the bytes returned. The bytes and byte type together must be valid if the
+// error is nil.
+type ValueMarshaler interface {
+	MarshalBSONValue() (bsontype.Type, []byte, error)
+}
+
+// Marshal returns the BSON encoding of val.
+//
+// Marshal will use the default registry created by NewRegistry to recursively
+// marshal val into a []byte. Marshal will inspect struct tags and alter the
+// marshaling process accordingly.
+func Marshal(val interface{}) ([]byte, error) {
+	return MarshalWithRegistry(DefaultRegistry, val)
+}
+
+// MarshalAppend will append the BSON encoding of val to dst. If dst is not
+// large enough to hold the BSON encoding of val, dst will be grown.
+func MarshalAppend(dst []byte, val interface{}) ([]byte, error) {
+	return MarshalAppendWithRegistry(DefaultRegistry, dst, val)
+}
+
+// MarshalWithRegistry returns the BSON encoding of val using Registry r.
+func MarshalWithRegistry(r *bsoncodec.Registry, val interface{}) ([]byte, error) {
+	dst := make([]byte, 0, 256) // TODO: make the default cap a constant
+	return MarshalAppendWithRegistry(r, dst, val)
+}
+
+// MarshalWithContext returns the BSON encoding of val using EncodeContext ec.
+func MarshalWithContext(ec bsoncodec.EncodeContext, val interface{}) ([]byte, error) {
+	dst := make([]byte, 0, 256) // TODO: make the default cap a constant
+	return MarshalAppendWithContext(ec, dst, val)
+}
+
+// MarshalAppendWithRegistry will append the BSON encoding of val to dst using
+// Registry r. If dst is not large enough to hold the BSON encoding of val, dst
+// will be grown.
+func MarshalAppendWithRegistry(r *bsoncodec.Registry, dst []byte, val interface{}) ([]byte, error) {
+	return MarshalAppendWithContext(bsoncodec.EncodeContext{Registry: r}, dst, val)
+}
+
+// MarshalAppendWithContext will append the BSON encoding of val to dst using
+// EncodeContext ec. If dst is not large enough to hold the BSON encoding of val, dst
+// will be grown.
+func MarshalAppendWithContext(ec bsoncodec.EncodeContext, dst []byte, val interface{}) ([]byte, error) {
+	sw := new(bsonrw.SliceWriter)
+	*sw = dst
+	vw := bvwPool.Get(sw)
+	defer bvwPool.Put(vw)
+
+	enc := encPool.Get().(*Encoder)
+	defer encPool.Put(enc)
+
+	err := enc.Reset(vw)
+	if err != nil {
+		return nil, err
+	}
+	err = enc.SetContext(ec)
+	if err != nil {
+		return nil, err
+	}
+
+	err = enc.Encode(val)
+	if err != nil {
+		return nil, err
+	}
+
+	return *sw, nil
+}
+
+// MarshalExtJSON returns the extended JSON encoding of val.
+func MarshalExtJSON(val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	return MarshalExtJSONWithRegistry(DefaultRegistry, val, canonical, escapeHTML)
+}
+
+// MarshalExtJSONAppend will append the extended JSON encoding of val to dst.
+// If dst is not large enough to hold the extended JSON encoding of val, dst
+// will be grown.
+func MarshalExtJSONAppend(dst []byte, val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	return MarshalExtJSONAppendWithRegistry(DefaultRegistry, dst, val, canonical, escapeHTML)
+}
+
+// MarshalExtJSONWithRegistry returns the extended JSON encoding of val using Registry r.
+func MarshalExtJSONWithRegistry(r *bsoncodec.Registry, val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	dst := make([]byte, 0, defaultDstCap)
+	return MarshalExtJSONAppendWithContext(bsoncodec.EncodeContext{Registry: r}, dst, val, canonical, escapeHTML)
+}
+
+// MarshalExtJSONWithContext returns the extended JSON encoding of val using Registry r.
+func MarshalExtJSONWithContext(ec bsoncodec.EncodeContext, val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	dst := make([]byte, 0, defaultDstCap)
+	return MarshalExtJSONAppendWithContext(ec, dst, val, canonical, escapeHTML)
+}
+
+// MarshalExtJSONAppendWithRegistry will append the extended JSON encoding of
+// val to dst using Registry r. If dst is not large enough to hold the BSON
+// encoding of val, dst will be grown.
+func MarshalExtJSONAppendWithRegistry(r *bsoncodec.Registry, dst []byte, val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	return MarshalExtJSONAppendWithContext(bsoncodec.EncodeContext{Registry: r}, dst, val, canonical, escapeHTML)
+}
+
+// MarshalExtJSONAppendWithContext will append the extended JSON encoding of
+// val to dst using Registry r. If dst is not large enough to hold the BSON
+// encoding of val, dst will be grown.
+func MarshalExtJSONAppendWithContext(ec bsoncodec.EncodeContext, dst []byte, val interface{}, canonical, escapeHTML bool) ([]byte, error) {
+	sw := new(bsonrw.SliceWriter)
+	*sw = dst
+	ejvw := extjPool.Get(sw, canonical, escapeHTML)
+	defer extjPool.Put(ejvw)
+
+	enc := encPool.Get().(*Encoder)
+	defer encPool.Put(enc)
+
+	err := enc.Reset(ejvw)
+	if err != nil {
+		return nil, err
+	}
+	err = enc.SetContext(ec)
+	if err != nil {
+		return nil, err
+	}
+
+	err = enc.Encode(val)
+	if err != nil {
+		return nil, err
+	}
+
+	return *sw, nil
+}