wip: Gemfile: use ruby-2.1.3
wip: update .gitignore

* ignore tmp files (front-end)
wip: rubygems: set `:require => false`
wip: rubygems: add juicer to build sinon.js
wip: rubygems: update Gemfile.lock
wip: app: change public_folder `public/` => `dist/`
wip: npm: add package.json

* gulp
* bower
wip: bower: add bower.json

* add dependencies
  * backbone
  * jquery
  * requirejs
  * underscore
* add devdependencies
  * mocha
  * chai
  * sinon
wip: gulp: add gulpfile.coffee

* gulp build
* gulp test
wip: requirejs: add requirejs_config.coffee for build
wip: repository_model: add repository_model.coffee
wip: app_router: add app_router.coffee
wip: requirejs: add requirejs_config.coffee for test
wip: app: add app.coffee

* load AppRouter class
wip: app: spec: add app_spec.coffee
wip: spec: add spec_helper.coffee
wip: spec: add test_runner.html
wip: test_controller: add test_controller.rb
wip: views: add index.slim
wip: travis: use ruby-2.1.3