Get all commits and not just the ones on the main branch (default: master)

[ninomllr]

When loading the commits the tap-gitlab only loads commits that are already on the main branch of a repository. All others are not loaded. I think this could be solved with the all flag? https://docs.gitlab.com/ee/api/commits.html

[aaronsteers]

@ninomllr - This makes sense to me. Do you feel this would be something you could contribute in a PR?

cc @pnadolny13, @tayloramurphy

[ninomllr]

@aaronsteers see here: #63