Update deps, include cachecontrol

vendor/github.com/pquerna/cachecontrol/doc.go

@@ -0,0 +1,25 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  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 cachecontrol implements the logic for HTTP Caching
+//
+// Deciding if an HTTP Response can be cached is often harder
+// and more bug prone than an actual cache storage backend.
+// cachecontrol provides a simple interface to determine if
+// request and response pairs are cachable as defined under
+// RFC 7234 http://tools.ietf.org/html/rfc7234
+package cachecontrol