Added username to user
Username must be unique and present
Fixed quotes
Changed quotation marks
Merge branch 'master' of https://github.com/LaunchAcademy/meta_review into add_username

Conflicts:
	app/models/user.rb
	spec/features/create_sites_spec.rb
	spec/features/user_signs_up_spec.rb
Created index for username
Revert "Created index for username"

This reverts commit 149159ce67ddf3603db7e6358a5086056f8bb615.
Added index for username
Merge pull request #23 from LaunchAcademy/add_username

Added username to user