Remove the /ci from the CI_SERVER_URL, because the v9.0.0 of the runner only supports GitLab >= 9.0.0, which has another endpoint. Also, the --user flag was removed.
Remove the /ci from the CI_SERVER_URL, because the v9.0.0 of the runner only supports GitLab >= 9.0.0, which has another endpoint. Also, the --user flag was removed.

gurinderu/dcos-gitlab-runner-service,tobilg/gitlab-ci-runner-marathon