RFR: notifier: add commit comment notifier

[Robin Westberg]

On Mon, 8 Jun 2020 15:34:16 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this patch that adds a new notifier - the commit comment notifier. The notifier is simple, it will add a
> comment to a pushed commit with links to the pull request and to fixed issues. This allows people to browse the history
> online and use the links in the comment to directly go to the review and/or issues (this already possible via CLI with
> the `git info` command).  Testing:
> - [x] Added two new unit tests
> - [x] `make test` passes on Linux x64
> 
> Thanks,
> Erik

Looks good!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/644