inital application
add Foursquare gem
initial categories setup
introduce tree structure for categories
add locale to categories
use GitHub version of awesome_nested_set
add schema
category output as tree
find categories by locale
import categories via Foursquare API
switch to passenger
sqlite3 only in development
complete switch to PostgreSQL
add Ruby version

https://devcenter.heroku.com/articles/ruby-versions
introduce locales
move routes root to categories
ORDER BY lft to avoid mix
default scope for categories
add support for category icons
include Foursquare attribution