Clean-up `docker-compose` files

[rgstephens]

Describe the bug
I worked with the docker-compose.dev.yml for a couple of days before realizing that it is pointing to an out of date image, papercups/papercups-dev. I kept searching for the API Key page and eventually figured this out.

I don't know the history of the three docker-compose files in the repo but it seems like maybe the prod repo should be renamed to docker-compose.yml and remove the other two.

I'm open to creating a PR for this if it makes sense.

Expected behavior
Would expect a dev image to use the most recent development release.

[cheeseblubber]

Yep that makes sense we'll merge it in thanks Greg!