Homework:
- implement the missing stuff from presentation:
- flash messages
- before filters
- simple_form
- Create a cat model:
- name (string) - required
- bio (text) - optional
- gender (string) - Male or Female
- Create a full controller for cat model like we did for users
- Create links in the header to 'all cats' and to 'all users'
- Make custom labels, hints, and placeholders for the cat form
- Display header according to user's session:
- show / hide register / sign in / sign out links
- display the user's email address (if signed in)
- Add all fields to devise user registration form
- Move header code in application.html.erb to a navbar partial (under views/layouts)