Passenger: https://www.phusionpassenger.com/library/deploy/apache/automating_app_updates/ruby/
DigitalOcean/Apache: https://www.digitalocean.com/community/tutorials/how-to-deploy-a-rails-app-with-passenger-and-apache-on-ubuntu-14-04
digitalocean.com: create Droplet (ubuntu 14.04.5 x32)