Please don't use a `FactoryGirl` method here*. Please read:

1. https://github.com/thoughtbot/factory_girl/blob/master/GETTING_STARTED.md#associations
2. http://arjanvandergaag.nl/blog/factory_girl_tips.html

on how to handle associations the right way.

*) I know that we use it the wrong way in the other factories. So, this is maybe a good time to fix this ;)