Cannot clone private (gitlab) repo

[mradke]

Node Version: 8.6.0
NPM Version: 5.3.0
Mac OS X Sierra
elm-grove tag 1.2.3

This is essentially a duplicate of #8 as far as I understand it, just in my case a private Gitlab instance is not working correctly.
With my private gitlab instance I cannot use the format of git@mygitlab.host.com:group/repository.git

The error I am receiving is (Error: Failed to authenticate SSH session: Callback returned error)

Please let me know if you need further information to identify the issue, or if I can help otherwise.