Older review shows up. Tests failing due to incrementing user_id.
Added #current bool to Review.

This will let us know if the Review is the most current the User has
submitted.
Oldest Review is now shown if updating a Review
Still need to update #current for last Review if the User is updating
it.
Things are looking up!
Review#current defaults to true when first created.
A user can now only have 1 review per repo.

The review persists DB side, but only the 1 is shown on repo#show.

As of now, the old review stays on the page until the page is refreshed.
FIXME ^
For now, a Review#rating is a drop down panel with 1..5

This needs to be refactored on the front end to use MAGICAL STARS!
Merge pull request #23 from benwoody/16b_one_review_per_user

16b one review per user