Support for GitLab Subgroups

GitLab allows an organization to have a hierarchy of Repos called Subgroups.

It would be very nice if we can configure this in hound and also allow filtering to any repo in a subproject.

Example:

https://gitlab.com/project/repo1
https://gitlab.com/project/subproject/*
  https://gitlab.com/project/subproject/repo2
  https://gitlab.com/project/subproject/repo3
  https://gitlab.com/project/subproject/subproject2/*
    https://gitlab.com/project/subproject/subproject2/repo4
    https://gitlab.com/project/subproject/subproject2/repo5

If choosing https://gitlab.com/project/subproject/* it will only search children and not return results from https://gitlab.com/project/repo1