Add workflow to ensure no merge commits are included

[Mab879]

Description:

I have been thinking about adding this check for while. This should reduce the load on maintainers and reduce the risk of a maintainer missing this style guide requirement.

Rationale:

Reduce load on maintainers.

Review Hints:

I can add a merge commit on request. Let me know if you want this.

[github-actions]

Start a new ephemeral environment with changes proposed in this pull request:

Fedora Environment

Oracle Linux 8 Environment

[codeclimate]

Code Climate has analyzed commit f80889f and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 61.8% (0.0% change).

View more on Code Climate.

[sej7278]

Might be worth adding documentation as to the preferred method for avoiding merge commits - squash, rebase etc.

[Mab879]

Might be worth adding documentation as to the preferred method for avoiding merge commits - squash, rebase etc.

We have sight preference for rebasing, see https://complianceascode.readthedocs.io/en/latest/manual/developer/04_style_guide.html#pull-requests.