Make real Openshift `.gitlab-ci.yml`template
Current template uses Openshift to build the docker image, but this means it can't (easily) be used for tests. A best practice is to build the docker image first, run tests on it, and then deploy. We should use GitLab runners to build the image and GitLab Registry to store them, then finally push to Openshift.
Also, I tried using a Node app with Openshift and it behaved really strangely, creating an image stream for the base image specified in the Dockerfile which then conflicted when creating another review app with the same base image. Maybe this will go away when we build the image ourselves, but something to be aware of. We need the Openshift template to work with real apps, not just httpd serving static files.