Updated model and controller to allow voting

* New column 'votes' on Idea model
* RESTful routes for IdeasController
* member action 'upvote' for IdeasController
* specs

USe XHR to update the votes

Finish xhr; use image

Feature specs
Added format, color and other options to Guardfile
Moved common body to before, separated assertions, changed expect to be on the results not the call to upvote
Merge branch 'f6_vote_for_an_idea'