If you create a trial account on GCP, you can then use GitLab to make a new GKE cluster and it will be automatically linked. You can then click a single button to deploy the Helm Tiller, a GitLab Runner, and then run your CI/CD jobs on your brand new cluster!
The GCP trial is pretty nice, you get $300 in credits and you won't be automatically billed at the end: https://cloud.google.com/free/