Add generated file

This PR adds generated files under pkg/client and vendor folder.

vendor/golang.org/x/tools/playground/appengine.go

@@ -0,0 +1,26 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appengine
+
+package playground
+
+import (
+	"net/http"
+
+	"appengine"
+	"appengine/urlfetch"
+)
+
+func init() {
+	onAppengine = !appengine.IsDevAppServer()
+}
+
+func client(r *http.Request) *http.Client {
+	return urlfetch.Client(appengine.NewContext(r))
+}
+
+func report(r *http.Request, err error) {
+	appengine.NewContext(r).Errorf("%v", err)
+}