Allow users to be followers and followed
Users should have relationships
Define the relationships for users
Require the follower_id and followed_it
Override 'followed' with 'followed_users'
Add helpers for follow! and following? users
Add helper to unfollow! users
Define followers relationship as reverse of followed_users
Refactor populate task
Display the follower/following stats for user

* The stats layout is in its own partial
* Add styling too
Create routes and partials to follow and unfollow users
Finish view for followers/followed user lists
Finish implementing follow/unfollow
Allow users to follow/unfollow with Ajax

This avoids refreshing the page when the button is clicked.
Initial implementation of user feed
Use subselect to improve the query