Test for presence of edit page and its failure on bad info
Add edit and update methods for Users

The update method does not yet handle successful updates yet.
Add a user edit form
Test for successful update and redirect on good profile update
Sign in users and redirect to their home page on successful updates.
Test for the presence of 'Edit Settings' when logged in
Add a 'Settings' link in the header when signed in
Add a sign_in utility method for rspec
Fix sign_in method (oops)
Check for authentication redirect when trying to edit other users
Redirect when trying to edit when not logged in
Sign in before trying to visit edit page in tests