Some invocations need it.

- Update the prospector pre-commit hook, it was failing for some reason.
- Address some docstring issues it started complaining about.

Sometimes Terraform or Packer are needed. This will make it as all that
will be needed is an `apt-get update && apt-get install -y terraform`
without making the image bigger than it needs to be.

In the Docker templates.

It should be a list of strings.

Oops, should have done that before.

This script does a better at checking the health of the Docker Compose
project.

The calling CI pipelines failed with the right error, but it was not in
the calling project's pipeline definition. It took me a while until the
penny dropped.

A lot of tools are packages there and saves a bit of a hassle.

Only on schedule or if the templates are changed.

Merge the ci-templates and ci-images repositories.

Can't mix and match or override rules and when.

There's really no point in it. I usually keep the master branch
buildable and working so running pre-commit is a waste of time and a
source for failed builds that shouldn't be.

Test all of the files in the repo, otherwise most (all?) hooks will not
even run.

See 0a1e7b83.

First of all, I'm replacing the hadolint hook that I maintained with the
one from https://github.com/AleksaC/hadolint-py and the docker-compose
hook with the new one I maintain at
https://git.shore.co.il/nimrod/pre-commit-hooks. Both don't require
Docker at all (just regular Python). Also, with
https://github.com/pre-commit/pre-commit/issues/1387 and then
https://github.com/pre-commit/pre-commit/issues/1918 resolved, the
original hooks that required Docker should work anyway.

I'm keeping the gitlab-ci hook disable for now, the 401 issue is still
present and there's little point in validating the CI config while it's
running (it is running after all).

The linter changed the usage and doesn't require the --file flag
anymore.