Merge pull request #4 from jedmund/feed

Added a Home Feed
Starting from scratch on an API-only application.
Made a Rails-API project
Added gems and code for Devise to work with rails-api
Installed Devise
Added models
Added public activity to Gemfile
Installed Public Activity
Migrated DB adding models
Added associations to models
Switched from SQLite3 to MySQL2
Added rudimentary validation to models
Factory Girl -> Factory Girl Rails
Installed Cucumber
shoulda-matchers
rspec
Added validate_url
Wrote tests. Made models pass them.
selenium-webdriver for cucumber
activities table migration didn't end in .rb