Merge pull request #18 from banana-slugs-2014/Darren_posts

comments work now on posts route, and such
Fix user model to create source on create, add seed data and test relational link
Merge pull request #19 from banana-slugs-2014/Seeds

Fix user model to create source on create, add seed data and test relati...
Username shows up next to comment with link and did some stuff with the navbar to make it so it only shows login or logout if no current user is there