Add: twitter-bootstrap-rails gem to the app  and generate layout
Add: views for Categories
Fix: typo in a good's association
Remove: unneeded gem 'activerecord-postgres-hstore'
Add: Good::HSTORE_ATTRIBUTES constant for holding hstore's keys
Remove: deprecated method 'all'
Add: view for Admin::GoodsController
Add: views for Admin::DashboardController
Add: Home controller
Add: Categories controller with index action