* don't fail when Git repo has no commit ([8ae334d](https://gitlab.com/to-be-continuous/tools/gitlab-cp/commit/8ae334d65e7d5ab07be6b84843262aeef69318d1))
* use subgroups API instead of descendant_groups ([ac5fad3](https://gitlab.com/to-be-continuous/tools/gitlab-cp/commit/ac5fad33a36e1e39917ffb75310c5c629442463c)), closes [#2](https://gitlab.com/to-be-continuous/tools/gitlab-cp/issues/2)