Added test to ensure mass assignment of admin is not allowed
Gravatar change link should now open in new tab/window
Added test to check for absense of links when user is not signed in
changed DRYing up auth test by using sign_in helper
DRYing up edit/signup forms, updated tests accordingly
Added redirect for signed in user when trying to access signup functionality
Added test to ensure the user is returned to the signin page on subsequent signin attempts
refactored users controller to prevent admin from deleting themselves