old_contents: import factory
  
  from zeus import models
  
  
  class RevisionFactory(factory.Factory):
      sha = factory.Faker('sha1')
      repository = factory.SubFactory('zeus.factories.RepositoryFactory')
      repository_id = factory.SelfAttribute('repository.id')
      date_created = factory.Faker('date_time')
      date_committed = factory.Faker('date_time')
  
      class Meta:
          model = models.Revision
  
new_contents: import factory
  import factory.faker
  
  from zeus import models
  
  
  class RevisionFactory(factory.Factory):
      sha = factory.Faker('sha1')
      repository = factory.SubFactory('zeus.factories.RepositoryFactory')
      repository_id = factory.SelfAttribute('repository.id')
      message = factory.faker.Faker('sentence')
      date_created = factory.Faker('date_time')
      date_committed = factory.Faker('date_time')
  
      class Meta:
          model = models.Revision
  
subject: add revision message to factory