Prepare app for Heroku deployment

Step by step:
$ heroku create
$ heroku addons:add mongolab

Add production details in mongoid.yml for MongoLab

Generate new secret token and set it on heroku:
$ rake secret
$ heroku config:set SECRET_TOKEN=[the token that was just generated]

$ heroku addons:add redistogo

Add config/initializers/geocoder.rb for Redis integration

Commit to git

$ git push heroku master