Don't require support/external_request from rake tasks

If we require this we're requiring everything that
support/external_request requires for production.

lib/tasks/factory_girl.rake

@@ -1,12 +1,9 @@
-require_relative '../../spec/support/external_request'
-
 namespace :factory_girl do
   desc "Verify that all FactoryGirl factories are valid"
   task lint: :environment do
     if Rails.env.test?
       begin
         DatabaseCleaner.start
-        mock_commercial_request
         FactoryGirl.lint
       ensure
         DatabaseCleaner.clean