Add Gitlab support to git clonefork

[Cali0707]

Currently, the git clonefork command depends on the Github API, so it will not work for any Gitlab repositories. To rectify this, a check should be added to see whether or not a repository is on Github vs Gitlab. Then, code to call the Gitlab API properly should be added as well.

[Cali0707]

Hold until after redesign that will be caused by #17