added comments to the gem show page
Merge pull request #18 from lauyeung/create-comment-model

added comments to the gem show page
removed compass rails from gemfile
Added tests that confirm a non-authenticated user can't review a gem or comment on a review.
Merge pull request #19 from lauyeung/check-foundation-without-compassrails

removed compass rails from gemfile
User can edit their review.