adding custom items to the CE activity feed

#models/my_thing.rb
class MyThing < ActiveRecord::Base
  belongs_to :user
  acts_as_activity :user
end

#views/activities/_unhandled_item.html.haml
- case activity.item_type
  - when 'MyThing'
    ="created a MyThing: #{link_to(activity.item.name, user_my_thing_path(activity.item.user, activity.item))}"