update rails dependency from '~> 4.1.0' to '~> 4.2.0' and update magellan-rails from 0.0.4 to 0.1.0
update VERSION from 0.3.3 to 0.4.0
rename `config.serve_static_assets` which is deprecated now to `config.serve_static_files`
add responders gem in order to upgrade rails-4.2.0
Merge pull request #26 from tengine/features/rails-4.2

rails-4.2.0 で動くように変更しました