Create a Dockerfile for running Airflow

[MthwRobinson]

The goal of this story is to create a docker image that (1) installs the data ingest package and (2) runs the Airflow scheduler and webserver. Optionally, the solution can use docker compose to set up a Postgres database to use as the backend for Airflow. Currently, Airflow is configured to use SQLite as a backend. Postgres would enable us to take advantage of multithreading. Another option would be to use the RDS, but I'd prefer to shut that down to save money.