added logic for showing new edit and delete post
added created_at for posts to represent date
removed feature specs

due to the nature of this blog I decided
to move away from feature specs and only
unit test controllers and models.
wrote controller tests for index

users, admins or the general public
has access to the any posts
wrote tests for posts new method

- an admin has acces to the new method
- for a user and a non-user CanCan::AccessDenied
is raised