feat(django_secret_key): dynamically generate a django secret key if one does not exist in the environment

[samoehlert]

this lets us remove secrets from the repo (even though they are not actually a big risk)

[github-actions]

File	Coverage
All files	84%	✅
config/consumers.py	78%	✅
config/urls.py	69%	✅
config/settings/base.py	70%	✅
config/settings/local.py	73%	✅
scram/route_manager/admin.py	85%	✅
scram/route_manager/models.py	70%	✅
scram/route_manager/views.py	88%	✅
scram/route_manager/api/serializers.py	73%	✅
scram/route_manager/api/views.py	83%	✅
scram/templates/403.html	91%	✅
scram/templates/404.html	91%	✅
scram/templates/base.html	99%	✅

Minimum allowed coverage is 50%

Generated by 🐒 cobertura-action against 39ff526

[crankynetman]

Looks great, thanks for this!