Airflow-livy-operators

Bump other python libraries' versions
improve helper.sh script

Bump other python libraries' versions
Importing is simplified thanks to the new plugin management system in Airflow

* Airflow 2.1.2 (no change)
* apache-airflow-providers-http 2.0.0 (no change)
* requests 2.26.0 (new dependency)
* Python 3.7, 3.8, 3.9 (no change)

New feature contributed: pull Spark logs into Airflow.

- Airflow 2.1.2 (no change)
- apache-airflow-providers-http 2.0.0 (new dependency)
- Python 3.7, 3.8, 3.9 (no change)

Fixed unit tests, included http hook dependency.

- Airflow 2.1.2
- Python 3.7, 3.8, 3.9 (no change)

Get rid of positional arguments and deprecated decorators

* Airflow 2.0.2 (no change)
* Python 3.7, 3.8, 3.9 (no change)

No code changes compared to 0.4.1, just denoting which versions are supported (python, airflow)