Meltano

Hello everyone! Has anyone encounter this error before ?
```Broken DAG: [/project/orchestrate/dags/meltano.py] Traceback (most recent call last):
  File "/project/orchestrate/dags/meltano.py", line 189, in create_dags
    _meltano_job_generator(schedule_export["schedules"].get("job"))
  File "/project/orchestrate/dags/meltano.py", line 132, in _meltano_job_generator
    if schedule["start_date"]:
KeyError: 'start_date'```
This is happening when I schedule a job. If there're no jobs (but just piplines) the dags get created correctly

Ah i think this might be a new bug that snuck in with <https://github.com/meltano/files-airflow/pull/27/files>

<https://github.com/meltano/files-airflow/pull/27/files#diff-e8bc08e1a018fdbe3b9fe6f92c343397b447642bef124427e6b45f71bc687350R128>

We can get this fixed up upstream. In the interim, if you wanna do a quick local fix, I think just changing that `if schedule["start_date"]:` to a `if schedule.get("start_date"):`   should do the trick.

Tracking issue - <https://github.com/meltano/files-airflow/issues/29>

I can confirm that the work around fixed the issue. Thank you!