Activities related to Che6 deployment

[l0rd]

This is about some of the activities that are described in the upstream epic eclipse-che/che#7321. In particular:

• Che Deployment on OpenShift should be as easy as on Docker - #6097
  • Verify and eventually fix all the Che runtime stacks on minishift - cf Keep in rh-che Dockerfiles only packages that are not suitable for upstream #155
• Che 6 OpenShift template - #7318 and Cleanup instructions and yaml files in different repositories #452
• Che 6 MiniShift add-on: make sure that the addon works with Che 6
• Docs: Deploy with OpenShift template / MiniShift add-on