Add test case for cloning a private git repository

For cloning the private repository username/password credentials are required.
The password can be replaced by a GitLab personal/project access token (glpat).

Closes #8

Signed-off-by: Norman Ziegner <norman.ziegner@ufz.de>
4 jobs for 8-test-git-interaction in 3 minutes and 4 seconds (queued for 1 second)