The ruby API shows an option to assign owner_usernames on create_group and update_group. The create_group seems to work (and the owner is there after the group is created) but it appears that owner_usernames are only assignable on createon the REST side of things. So we can’t promote a user to an existing group owner without the UI (at least with the Ruby API).
Is this by design or is this worth a PR? Am I correct in assuming the Ruby side of things would need matching methods for groups#add_owners and groups#remove_owner?