Creates user-bar many to many relationship through bar_gig_memberships

* Creates owner-owned bar relationship
* Generates bar_gig_membership model
* Adjusts partials to display new associations
Ahh! Law of demeter!
http://devblog.avdi.org/2011/07/05/demeter-its-not-just-a-good-idea-its-the-law/
ideal scenario is to make bar.owner_name to work