disables js fx in specs via poltergeist config

spec/rails_helper.rb

@@ -28,7 +28,8 @@ Capybara.register_driver :poltergeist do |app|
   Capybara::Poltergeist::Driver.new(app,
     inspector: true, # allows remote debugging by executing page.driver.debug
     phantomjs_logger: File.open(File::NULL, "w"), # don't print console.log calls in console
-    phantomjs_options: ['--load-images=no', '--disk-cache=false']
+    phantomjs_options: ['--load-images=no', '--disk-cache=false'],
+    extensions: [File.expand_path("../support/phantomjs_ext/disable_js_fx.js", __FILE__)] # disable js effects
   )
 end