added deprecation warnings to file_storage

lib/google/api_client/auth/file_storage.rb

@@ -34,11 +34,17 @@ module Google
                     :path
 
       def initialize(path)
+        Google::ApiClient.logger("DEPRECATED: Please use Storage Class instead.")
         @path = path
         store = Google::APIClient::FileStore.new(@path)
         @storage = Google::APIClient::Storage.new(store)
       end
 
+      def load_credentials
+        Google::ApiClient.logger("DEPRECATED: Please use Storage Class instead.")
+        storage.authorize
+      end
+
       def authorization
         storage.authorization
       end