8.5 Exercise #1: form_tag
Chapter 8.5 Exercise #2 done... I think?
9.1.2 Unsuccessful edits
9.2.1 Requiring Signed in Users
9.2.3 Friendly Forwarding
9.3.1 User index
9.3.2 Sample users
9.3.4 Partial refactoring
9.5 Finish user edit, update, index and destroy actions