[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go
new file mode 100644
index 0000000..47922c4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go
@@ -0,0 +1,45 @@
+// Copyright 2017 The etcd Authors
+//
+// 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3client provides clientv3 interfaces from an etcdserver.
+//
+// Use v3client by creating an EtcdServer instance, then wrapping it with v3client.New:
+//
+//	import (
+//		"context"
+//
+//		"go.etcd.io/etcd/embed"
+//		"go.etcd.io/etcd/etcdserver/api/v3client"
+//	)
+//
+//	...
+//
+//	// create an embedded EtcdServer from the default configuration
+//	cfg := embed.NewConfig()
+//	cfg.Dir = "default.etcd"
+//	e, err := embed.StartEtcd(cfg)
+//	if err != nil {
+//		// handle error!
+//	}
+//
+//	// wrap the EtcdServer with v3client
+//	cli := v3client.New(e.Server)
+//
+//	// use like an ordinary clientv3
+//	resp, err := cli.Put(context.TODO(), "some-key", "it works!")
+//	if err != nil {
+//		// handle error!
+//	}
+//
+package v3client