Write spec for UsersController#show.
Allow users to edit and update their profile.

Implementation details and notes:

* Create Profile controller for handling current_user profile edits and updates
* Create form for Profile edit
* Display Edit Profile link on the user profile if the user is the current user

Pivotal Tracker ID: 63205854
https://www.pivotaltracker.com/story/show/63205854
Merge pull request #61 from opscode/63205854_update_user_profile

Allow users to edit and update their profile.