One-to-Many: Nested Resources
 Changes to be committed:
	modified:   app/controllers/registrations_controller.rb
	modified:   app/models/event.rb
	modified:   app/models/registration.rb
	modified:   app/views/events/show.html.erb
	new file:   app/views/registrations/index.html.erb
	modified:   config/routes.rb
	modified:   db/seeds.rb