clean up / format / poetry (#1000)

* stub in poetry for pipenv

* re-add tester image

* add pre-commit / formatting

* fix ghactions

* revert test data whitespace, exclude tests/data

* revert ws

* decruft, rm tox/pipenv

* install dev packages for base image

* add lgtm config to force to py3

tests/test_cmd_pdb_cleanup_vq.py

@@ -1,10 +1,10 @@
-from datetime import datetime, timezone, timedelta
-import pytest
 import random
 import string
+from datetime import datetime, timedelta, timezone
 
-from django.contrib.contenttypes.models import ContentType
+import pytest
 from django.conf import settings
+from django.contrib.contenttypes.models import ContentType
 from django.core.management import call_command
 from django.test import override_settings