update Rails to 4.2.0

.travis.yml

@@ -8,3 +8,4 @@ rvm:
 env:
   - RAILS='~> 4.0.8'
   - RAILS='~> 4.1.4'
+  - RAILS='~> 4.2.0'

Gemfile

@@ -9,7 +9,7 @@ platforms :rbx do
   gem 'rubinius-developer_tools'
 end
 
-rails = ENV['RAILS'] || '~> 4.1.4'
+rails = ENV['RAILS'] || '~> 4.2.0'
 
 gem 'rails', rails