add new model Relationship
migrate

relationship
add test cases

establish relationship
add test cases

respond_to? :relationships
add foreign key 'follower_id' to user
foreign key
add test cases

when followed id is not present and when follower id is not present
validates follower_id and followed_id
add test cases

respond_to? followed_users
followed_users
add test cases

following
follow
add test cases

unfollowing
unfollow
add test cases

followed users
followers
sample date
add routes
add test cases

follower/following counts
local view of stats