Cannot deploy single content_entry with the Wagon

[adam-pl]

REPRO

1. Create new project & two models: categories, groups
2. Deploy all to the Engine
3. Edit data/categories.yml and do some changes (on the Wagon site)
4. Try to deploy only categories.yml to the Engine like that:

bundle exec wagon push my_site -v -d -r content_entries -f categories

WHAT'S WRONG

1. The Wagon pushes all content entries: categories & groups

HOW IT SHOULD BE

1. The Wagon should push only categories content entry.

[did]

That's because Categories and Groups are related through a belongs_to/has_many or a many_to_many relationship.