Add edit/update page.
Add authorization user's pages - only signed in user can edit his data.
Add friendly forwarding.
Create index page with all users for singed in users and add 99 demo users to DB with 'faker' gem.
Paginate index page.
Refactor index page to use partial + automatic iteration for all users.
Add delete option to admins (additional user parameter) with all appropriate security issues.
Finish user edit, update, index, and destroy actions - only exercises 1, 5 and 8 are solved (TODO).