Airflow Meetup Slides and testing sample code

[George Leslie-Waksman <ge...@cloverhealth.com.INVALID>]

Since there seemed to be a lot of interest in how we're using pytest
fixtures to test dags and postgres, I have thrown together a minimal repo
with some code samples that show how we do some of our testing:
https://github.com/CloverHealth/aftest_examples

I have also included the slides from my talk at Wedsneday's meetup in the
root of the repo.

--George