Extend docker test with deploy check

[foarsitter]

As the docs already mention, manage.py check --deploy requires the production settings, otherwise it fails on security related settings. In turn, running the production settings require the production dependencies.

This PR references the production requirements in requirements/local.txt so the dependencies like collectfast are available during development. This gives us the possibility to use the production settings in the local docker image and run check --deploy. For convenience I added the --database to check since they aren't run by default.

Fixes #4462

[browniebroke]

I was thinking of adding more job to the CI, but actually that's much better.

Do you think it would be worth changing test_bare.sh to run this deploy check as well?

I haven't thought about this much, and I'm assuming that it's a similar level of complexity as test_docker.sh. If it's more complicated than that (need extra services to be runnning on CI), I wouldn't do it as part of this PR.

[foarsitter]

Do you think it would be worth changing test_bare.sh to run this deploy check as well?

I don't think it is worth it since the production settings do not contain any logic that differ between bare and docker.

[browniebroke]

Do you think it would be worth changing test_bare.sh to run this deploy check as well?

I don't think it is worth it since the production settings do not contain any logic that differ between bare and docker.

fair enough. Anyway, LGTM! I will feel a tiny bit more confident in merging updates to our prod dependencies now. Thanks for that.