upgraded rails to 4.2 and dependencies. except rubocop

spec/spec_helper.rb

@@ -79,6 +79,7 @@ RSpec.configure do |config|
   config.include Flash, type: :feature
   config.include Sidebar, type: :view
   config.include Devise::TestHelpers, type: :view
+  config.include Capybara::DSL
 
   # As we start from scratch in April 2014, let's forbid the old :should syntax
   config.expect_with :rspec do |c|

spec/support/save_feature_failures.rb

@@ -3,7 +3,7 @@
 RSpec.configure do |config|
   config.after(:each, type: :feature) do
     ename = RSpec.current_example.full_description
-    ename = ename.gsub ' ', '_'
+    ename = ename.tr ' ', '_'
     ename.downcase!
     ename = ename + '.html'
     if RSpec.current_example.exception.present?