Expand automatic testing to include all CLI commands about rke

[manuelbuil]

Update: I carried out a quick investigation on possible options to do this:

1 - Enhance our current CI which uses docker to create nodes. But this is limited and not testing a typical rke deployment
2 - Change CI and start using nested virtualization in the drone ec2 to create the extraVM we need. Run rke binary in drone-runner and deploy k8s in the extraVM
3 - Change CI and add terraform code to what gets executed in drone-runner. That terraform code creates the extraVM. Run rke binary in drone-runner and deploy k8s in the extraVM
4 - Change CI. Stop using drone and start using github-actions + macos + vagrant to do the nested virtualization. But the cpu resources are quite limited and it has currently a bug

EOI is already using option 2 for harvester, so we are going to prioritize that one as we can tap on that already existing WoW and experience. The great thing is that they'll take care of creating the extra VM for us, which is awesome. My main concern is price, as aws-ec2 instances that allow nested virtualization cost x10 more but as rke1 does not have a lot of PRs, the price should not be prohibitively.

EOI team is currently building a PoC to verify this. Once they are ready we'll give it a try and hopefully is fulfills our needs!

[manuelbuil]

Kinara commented that after upgrades some features get broken. We should test it too!