hi,team:

    my dag is 1 minute schedule,one parts dag state is success,but tasks state is not yet started in a dag:

![image](https://user-images.githubusercontent.com/41068725/116344664-357d8780-a819-11eb-8010-c746ffdfdbcc.png)


   how can to fix it?
tests/core/test_sqlalchemy_config.py
self, mock_create_engine, mock_sessionmaker, mock_scoped_session, mock_setup_event_handlers
    ):
        config = {
            ('core', 'sql_alchemy_connect_args'): 'does.not.exist',
            ('core', 'sql_alchemy_pool_enabled'): 'False',
        }
        with pytest.raises(AirflowConfigException):
            with conf_vars(config):
                settings.configure_orm()