Build site on deploy

* Add Ruby 2.0 to Gemfile
* Add rake-pipline to trigger the assets:precompile
* Add Unicorn web server
* Add Procfile for Heroku deploys

Minor changes:

* Add gitignore file
* Add config.rb so Middleman can build
* Add sample index page
Merge pull request #4 from harlow/hw-unicorn-as-web-server

Get deploy running on Heorku