Added votes model and migration
Added upvote / downvote.  Added average rating to index page.  Added sorting reviews by upvote/downvote count.
Added destroy methods
Merge branch 'master' into upvote
added save to helper methods for updating counter cache on review votes
Fixed callback methods for vote creating, updating, and destroying
Fixed ordering of reviews by upvote count desc
Added user_id to foodtrucks table.  Added user seeds
Add review votes test
Fix user login and downvote count
Merge pull request #21 from saltys/add_votes_test

Add review votes test
Fixed issues related to pull request comments.
Fixed destroy for votes
Merge pull request #19 from Maimer/upvote

Upvote
Fix merge conflicts