Warning when about to merge a "fixup!" commit

Sometimes you don't realize that after code review someone pushed another commit to a pull-request. Those commits are usually named "fixup! …" to allow auto-squashing on rebase operations.

If you don't realize that, you end up with a Fixup-Commit in your master branch.

I'd suggest a simple warning popup if you're about to merge a branch/pull-request that contains commits starting with "fixup! …"