Add Danger, add myself to CODEOWNERS
This adds Danger integration using:
- Default rule checks
- Reviewer roulette
I simplified the roulette template compared to other repos so that we do not categorize folders and removed some language that was specific to the GitLab repo. (I had actually copied this template from Gitaly.)
Added myself to CODEOWNERS as well. We don't have a good solution yet to keep all of this stuff in sync.
Edited by Matthias Käppler