GitLab Integration

[amilosevic-grid]

From what I see, for github integration, gh CLI tool is used.
In a similar way GitLab can be integrated in a similar way using the glab CLI tool as well.

I have been using roborev for a while and I use it for personal projects that I put on Github, but I would also love to integrate it on the CI for company projects on GitLab.

Would you accept a PR on this? @wesm

[wesm]

Sure, I think the exiting CI poller infrastructure should be able to be used to provide the same kind of experience