Switch to using the dep tool and update all the dependencies

vendor/google.golang.org/appengine/internal/api_race_test.go

@@ -0,0 +1,9 @@
+// Copyright 2014 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+// +build race
+
+package internal
+
+func init() { raceDetector = true }