Aio-geojson-geonetnz-volcano

* Bump aio_geojson_client to 0.21.
* Removed Python 3.8 support.
* Code quality improvements.

* Bumped version of upstream aio_geojson_client library to 0.20.
* Improved JSON parsing error handling, especially when not using Python's built-in JSON parsing library.
* Code quality improvements.
* Added Python 3.12 support.
* Removed Python 3.7 support.
* Bumped library versions: black, flake8, isort.
* Migrated to pytest.

* Added Python 3.11 support (thanks fabaff).
* Removed deprecated asynctest dependency (thanks fabaff).
* Bumped version of upstream aio_geojson_client library to 0.18.

* No functional changes.
* Added Python 3.10 support.
* Removed Python 3.6 support.
* Bumped version of upstream aio_geojson_client library to 0.16.
* Bumped library versions: black, flake8, isort.
* Migrated to github actions.

* Python 3.9 compatibility.
* Add license tag.
* Bump aio_geojson_client to v0.14.
* Set aiohttp to a release 3.7.4 or later (thanks fabaff).
* General code improvements.

* Python 3.8 compatibility.