Make single codebase roulette respect OOO status
What does this MR do?
- Extract Danger roulette to its own module
- Make single codebase roulette respect OOO status
This was extracted from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/28678 due to the concern of not sharing the code: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/28678#note_175777251
We can see that https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13297#note_174299584 and https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13430#note_174948612 should benefit from checking OOO.
Result for single codebase:
Result for the regular review:
Edited by Lin Jen-Shin