gem 'rolify'
rails generate rolify:role Role User
Add admin user
gem 'activeadmin'
rails generate active_admin:install --skip-users
Use existing User model for ActiveAdmin authentication/authorization
db/schema.rb
rails generate active_admin:resource tour
rails generate active_admin:resource category
Customize ActiveAdmin view for tours
gem 'cancan'
rails generate cancan:ability
Add simple authorization

* Guests and registered users can read everything
* Admins can manage everything
Only show links if you're authorized
Use CanCan for ActiveAdmin authorization
Allow users to edit their own tours