Add omniauth-twitter gem
Add SessionsController
Require login for TweetersController#show

* Add twitter_client param to Tweeter#most_favorited/retweeted_tweeters
Add Twitter credentials to tweeters table

* Add Tweeter#access_token
* Add Tweeter#access_token_secret
Add twitter auth
Remove Sessions#create view
Remove out-of-date controller specs
Remove pending specs
Merge pull request #5 from jakeboxer/twitter-auth

Add per-user Twitter auth