Use Rails 4 as default environment for testing

Author: pkuczynski

spec/spec_helper.rb

@@ -19,7 +19,7 @@
 if ENV['APPRAISAL_INITIALIZED'] || ENV['TRAVIS']
   app_name = Pathname.new(ENV['BUNDLE_GEMFILE']).basename.sub('.gemfile', '')
 else
-  app_name = 'rails_3'
+  app_name = 'rails_4'
 end
 
 require File.expand_path("../../spec/app/#{app_name}/config/environment", __FILE__)