Using a 2.0.0 beta 2 build...

![Untitled](https://user-images.githubusercontent.com/4283/99546252-3ebe1a80-2984-11eb-9681-8d6e718b22c5.gif)

Log from webserver:

```
[2020-11-18 14:58:52,712] {interface.py:713} ERROR - Delete record error: Dependency rule tried to blank-out primary key column 'job.id' on instance '<SchedulerJob at 0x7fc68ba7f990>'
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/flask_appbuilder/models/sqla/interface.py", line 698, in delete
    self.session.commit()
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/scoping.py", line 163, in do
    return getattr(self.registry(), name)(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1042, in commit
    self.transaction.commit()
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 504, in commit
    self._prepare_impl()
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 483, in _prepare_impl
    self.session.flush()
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2536, in flush
    self._flush(objects)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2678, in _flush
    transaction.rollback(_capture_exception=True)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
    with_traceback=exc_tb,
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 182, in raise_
    raise exception
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2638, in _flush
    flush_context.execute()
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/unitofwork.py", line 422, in execute
    rec.execute(self)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/unitofwork.py", line 538, in execute
    self.dependency_processor.process_deletes(uow, states)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/dependency.py", line 547, in process_deletes
    state, child, None, True, uowcommit, False
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/dependency.py", line 604, in _synchronize
    sync.clear(dest, self.mapper, self.prop.synchronize_pairs)
  File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/sync.py", line 88, in clear
    "column '%s' on instance '%s'" % (r, orm_util.state_str(dest))
AssertionError: Dependency rule tried to blank-out primary key column 'job.id' on instance '<SchedulerJob at 0x7fc68ba7f990>'
172.19.0.1 - - [18/Nov/2020:14:58:52 +0000] "POST /dagrun/delete/147 HTTP/1.1" 302 415 "http://localhost:8080/dagrun/list/?_flt_3_dag_id=airflow_community_data_refresh&_flt_3_state=success" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.193 Safari/537.36"
```
tests/models/test_dagrun.py
dr.update_state()
        dr2.update_state()
        self.assertEqual(dr.state, State.RUNNING)
        self.assertEqual(dr2.state, State.RUNNING)
        ti2_op1.set_state(state=State.RUNNING, session=session)
        dr.update_state()
        dr2.update_state()
        self.assertEqual(dr.state, State.RUNNING)
        self.assertEqual(dr2.state, State.RUNNING)
    def test_dagrun_success_callback(self):
        def on_success_callable(context):
            self.assertEqual(context['dag_run'].dag_id, 'test_dagrun_success_callback')
        dag = DAG(
            dag_id='test_dagrun_success_callback',
            start_date=datetime.datetime(2017, 1, 1),
            on_success_callback=on_success_callable,
        )
        dag_task1 = DummyOperator(task_id='test_state_succeeded1', dag=dag)
        dag_task2 = DummyOperator(task_id='test_state_succeeded2', dag=dag)
        dag_task1.set_downstream(dag_task2)
        initial_task_states = {
            'test_state_succeeded1': State.SUCCESS,
            'test_state_succeeded2': State.SUCCESS,
        }
        dag_run = self.create_dag_run(dag=dag, state=State.RUNNING, task_states=initial_task_states)
        _, callback = dag_run.update_state()
        self.assertEqual(State.SUCCESS, dag_run.state)
        
        self.assertIsNone(callback)
    def test_dagrun_failure_callback(self):