coderanger
`git merge` doesn't seem to have any particularly obvious way to do the equivalent of `-s` which makes me think we should probably just ignore any multi-parent commit. The flipside is that is isn't impossible for a merge commit to introduce non-trivial code contributions if there was a merge conflict, so for safety it might be better to check for them. UX-friendly middle ground might be to have `dco sign` update merge commits but have dcob and `dco check` not require them. What does dcob do currently? /cc @robbkidd @thommay @nathenharvey @adamhjk