https://www.cloudpipes.com/integrations/github/gitlab-ci
https://about.gitlab.com/2015/01/22/gitlab-7-7-and-ci-5-4-re...
With gitlab-ci build descriptor you can do all you want so maybe you can ignore the gitlab repos and clone from other source, run tests, give the tests output to the gitlab runner ad see results on gitlab console.
(maybe)