Added authorize code to the application controller.  I added 'if' statements to the User Controller for edit, update and destroy.  I also did some mild refactoring replacing 'User.find(session[:current_user_id]) with 'current_user'.
We also updated the Users Show Edit button link to be a get method, because button_to automatically makes a post request.

I did not make any changes to locations controller because we do not currently have 'edit' or 'update' routes in the locations controller.
Merge pull request #15 from jjlee5266/authorize

Users Authorization Code