[1 day] Setup authenticating to this cluster from our deployer

[GeorgianaElena]

Tip: investigate using the kubeconfig method we already use for Azure

[sgibson91]

We already have an auth_kubeconfig function in the deployer's infrastructure so this task does not actually require any development of the deployer.

We should verify that this works for Jetstream2/OpenStack though, so the steps we should take to complete this task are:

• Following the tutorial, export the KUBECONFIG to a file (relevant commands are just above the "Scale manually" section)
• Save that file in our config/clusters directory and sops-encrypt it
• Run deployer use-cluster-credentials and ensure k get nodes returns something