'Test that we can de-register a processor.'

def test_deregister(self):

    self.site.external_manager.register_processor(DummyCriticalFailingProc)
    self.assertRaises(ExternalFailure, self.site.build)
    self.site.external_manager.deregister_processor(DummyCriticalFailingProc)
    self.site.build()
