Support fast forward merges with sign-offs
### Problem to solve
Our DevOps team uses fast forward merges. The persons, who do the merges, add their sign-offs to document the review. So merging a merge request looks like:
```
git checkout master
git cherry-pick --signoff master..$feature
git push
```
We like to use the merge proposal feature of GitLab with our workflow.
### Intended users
* Sasha (Software Developer)
* Devon (DevOps Engineer)
* Sidney (Systems Administrator)
### Further details
See problem description above.
### Proposal
Please add an option to Settings -> General -> "Merge requests" -> "Merge options" named "Sign-off commits when merging" and maybe have that option also on the merge proposal page as well.
### Permissions and Security
Every person that is allowed to merge a branch should be also have the permission to merge it with an sign-off.
### Documentation
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### Testing
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### What does success look like, and how can we measure that?
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### Links / references
> -s --signoff Add Signed-off-by line by the committer at the end of the commit log message. The meaning of a signoff depends on the project, but it typically certifies that committer has the rights to submit this work under the same license and agrees to a Developer Certificate of Origin (see http://developercertificate.org/ for more information).
https://git-scm.com/docs/git-commit#git-commit--s
issue