'Test that any template directories added are not cleared when microsites are enabled.'

def test_add_lookup_to_main(self):

    add_lookup('main', 'external_module', __name__)
    directories = LOOKUP['main'].directories
    self.assertEqual(len([directory for directory in directories if ('external_module' in directory)]), 1)
    startup.enable_microsites()
    directories = LOOKUP['main'].directories
    self.assertEqual(len([directory for directory in directories if ('external_module' in directory)]), 1)
