Before 7.2.3
Finish user signup
Add SSL in production
Exercise 7.6.1: COMPLETED
Exercise 7.6.2: COMPLETED
Exercise 7.6.3: COMPLETED
Exercise 7.6.4: broken users_controller.rb, show.html.erb (as suggested)
Exercise 7.6.4: COMPLETED, fixed broken stuff from last commit
Exercise 7.6.5: COMPLETED, content_tag added, and tested OK in application.html.erb