Rename followings table
Remove Followings model, add Subscription model
Update User model
Add tests for email, config Factory Girl
Add tests for Post model
Add tests for user mention email
Change subscriptions table to relationships, rename columns
Add User associations, followed_users & followers
Move registrations controller back into Users folder
Add User follow
Add AJAX reload of follower count on users#show
Add send email to User upon being followed :muscle: