Delete model-mommy instance

Question

I'm using model-mommy to generate test data like so

class AuthorDetailViewTests(TestCase):

    def setUp(self):
        # set bio manually to avoid error being thrown by template tag markdown_format
        self.author = mommy.make('author.Author', bio='Some bio text')

    def tearDown(self):
        self.author.delete()

setUp() method works fine. Problem is that the tearDown() method doesn't actually delete the created aauthor instance. Is there any way to achieve this? Thanks