updated styles for sticky-footer effect
created retweets table, which belongs_to both :user and :tweet. from tweet#show view, user can retweet. user can view a list of their retweets on user#show.
user can only retweet other users tweets
fixed navbar display with box-sizing. updated readme to remove gravatar user story
made small edit because something went wrong with last commit/push
Merge pull request #13 from gregRV/user-can-retweet

User can retweet