Flambé

Results 2 issues of Flambé

I have been running this package in Composer Airflow using a separate PyPi release I made for my team to use: ([airflow-dbt-cta](https://pypi.org/project/airflow-dbt-cta/)). I hope this will be only a temporary...

This avoids passing in an empty `env` to `subprocess.Popen(`, which results in `dbt command not found` errors when running this code in Composer Airflow