Prevent unintended expenses due to testing

[tompscanlan]

Is your feature request related to a problem? Please describe.

I'm very new to idem and azure. I was poking around this code base and ran tests which failed multiple times due to incorrect setup on my part. On failure, some resources are left behind and need to be manually cleaned up. Some of those can be pretty expensive, more so when you leave for PTO in the middle of poking around :)

Describe the solution you'd like

At the least, I think we should document that behavior. Beyond that, maybe make sure tests always remove all created resources after tests or failure.

Describe alternatives you've considered

1. Consider my personal choices in life and don't do this again?
2. mark some tests as expensive and by default don't run expensive tests. Attached images call out psql, bastion, and redis as main offenders that I ran into
3. make sure all resources get a specific tag so we can identify and delete zombies

Additional context

[tompscanlan]

I'll most likely add this if it sounds reasonable.

[Ajnbro]

I'll most likely add this if it sounds reasonable.

@tompscanlan That all sounds reasonable to me, thank you very much 😃.

Additionally, any remaining failing tests should be fixed when #204 is merged (this issue was also addressed by #202).