Add webmock for external requests in tests

external_request.rb needs to be required before lint is run.

Gemfile.lock

@@ -130,6 +130,8 @@ GEM
       simplecov (>= 0.7)
       term-ansicolor
       thor
+    crack (0.4.2)
+      safe_yaml (~> 1.0.0)
     currencies (0.4.2)
     daemons (1.1.9)
     database_cleaner (1.3.0)
@@ -409,6 +411,7 @@ GEM
     ruby-openid (2.5.0)
     ruby-progressbar (1.7.5)
     rubyzip (1.0.0)
+    safe_yaml (1.0.4)
     sass (3.2.19)
     sass-rails (4.0.4)
       railties (>= 4.0.0, < 5.0)
@@ -464,6 +467,9 @@ GEM
       binding_of_caller (>= 0.7.2)
       railties (>= 4.0)
       sprockets-rails (>= 2.0, < 4.0)
+    webmock (1.20.4)
+      addressable (>= 2.3.6)
+      crack (>= 0.3.2)
     websocket-driver (0.3.3)
     whenever (0.9.2)
       activesupport (>= 2.3.4)
@@ -553,6 +559,7 @@ DEPENDENCIES
   turbolinks
   uglifier (>= 1.3.0)
   web-console (~> 2.0)
+  webmock
   whenever
 
 BUNDLED WITH