GitLab Rancher Integration

Rancher is interested in building an integration with GitLab and there's already a community contribution of this: https://github.com/rancher/community-catalog/tree/master/templates/gitlab

Adrianne from their team will test our current helm chart (https://gitlab.com/charts/charts.gitlab.io) to understand it's compatibility with Rancher and expand on that.

Goals:

1. Deploy GitLab to Rancher
2. Allocate resources for review apps, CI
3. Deploy from GitLab CI to Rancher
4. Update GitLab container registry from Rancher