---
- group_milestones: milestones = GET groups/:group_id/milestones?
- group_milestone: milestone = GET groups/:group_id/milestones/:milestone_id
- create_group_milestone: milestone = POST groups/:group_id/milestones?
- edit_group_milestone: milestone = PUT groups/:group_id/milestones/:milestone_id?
- group_milestone_issues: issues = GET groups/:group_id/milestones/:milestone_id/issues?
- group_milestone_merge_requests: merge_requests = GET groups/:group_id/milestones/:milestone_id/merge_requests?
