gemfile cleanup, unicorn

Look https://devcenter.heroku.com/articles/getting-started-with-rails4#webserver

Also, v sublime user prefse si dodej:
```
"tab_size": 2,
"ensure_newline_at_eof_on_save": true,
"translate_tabs_to_spaces": true,
"trim_trailing_white_space_on_save": true
```