```ruby
FactoryGirl.define do
  factory :promotion, class: Spree::Promotion, parent: :activator do
    name 'Promo'
  end
end
```

Remove Activator class, rename spree_activators to spree_promotions
user
```ruby
FactoryGirl.define do
  factory :promotion, class: Spree::Promotion do
    name 'Promo'
  end
end
```
assistant