Added filter for upvotes
Added function and button to addPosts to posts
Added form for getting title, appending new post, and preventing blank input for title
Added click-able element for upvoting, added incrementUpvotes function for posts
Added link field for posts;use ng-show and ng-hide for link showing
Added Bootstrap styling
Created posts factory/service
Injected posts service into MainCtrl
Added Angular ui-router library and dependency