Add `unicorn` gem
Create file for unicorn
Add staging environment
Add capistrano gem
$ bundle exec cap install
Enable to deploy staging
Add capistrano plugin gems
Enable to use capistrano plugin
Add rbenv configuration
Set rails_env
Capistrano requires Gemfile.lock

see http://stackoverflow.com/questions/26477139/bundler-fails-with-cap-production-deploy
Remove specify `config/database.yml` in .gitignore
Enable to bundle install and restart unicron when cap deploy
Merge pull request #1 from a-know/sanchamoku2-20141101

三茶でもくもく会 #3（2014/11/01）