Fix bug in mock method (missing argument).

This should have been part of commit 70cc64ee.

test/test_helper.rb

@@ -39,7 +39,7 @@ require 'geocoder'
 #
 module Geocoder
   module Lookup
-    def self.fetch_raw_response(query)
+    def self.fetch_raw_response(query, reverse = false)
       File.read(File.join("test", "fixtures", "madison_square_garden.json"))
     end
   end