Fix dependencies

vendor/google.golang.org/appengine/timeout.go

@@ -1,20 +0,0 @@
-// Copyright 2013 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.
-
-package appengine
-
-import "golang.org/x/net/context"
-
-// IsTimeoutError reports whether err is a timeout error.
-func IsTimeoutError(err error) bool {
-	if err == context.DeadlineExceeded {
-		return true
-	}
-	if t, ok := err.(interface {
-		IsTimeout() bool
-	}); ok {
-		return t.IsTimeout()
-	}
-	return false
-}