include faraday_middleware gem to fix the :json issue

Gemfile

@@ -8,6 +8,7 @@ gem 'rails', '3.2.15'
 gem 'json'
 gem 'thin'
 gem 'faraday'
+gem 'faraday_middleware'
 gem 'yajl-ruby'
 gem 'excon'
 gem 'haml'

Gemfile.lock

@@ -65,6 +65,8 @@ GEM
       railties (>= 3.0.0)
     faraday (0.8.8)
       multipart-post (~> 1.2.0)
+    faraday_middleware (0.9.0)
+      faraday (>= 0.7.4, < 0.9)
     feedzirra (0.2.1)
       curb (~> 0.8.1)
       loofah (~> 1.2.1)
@@ -211,6 +213,7 @@ DEPENDENCIES
   excon
   factory_girl_rails
   faraday
+  faraday_middleware
   feedzirra
   haml
   jquery-rails