Reuse `base_and_ancestors` for `ancestors` in `GroupHierarchy`
Reuse `base_and_ancestors` for `ancestors` in `GroupHierarchy`

dreampet/gitlab,iiet/iiet-git,jirutka/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,dreampet/gitlab,dreampet/gitlab,stoplightio/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,dreampet/gitlab,mmkassem/gitlabhq,stoplightio/gitlabhq