Drop cluster.k8s.io

[enxebre]

This drops support for cluster.k8s.io
We are transitioning the cluster API types from k8s.io over a machine.openshift.io group.
https://github.com/openshift/cluster-api/tree/91fca585a85b163ddfd119fd09c128c9feadddca
Although this give us a necessary level of autonomy today, we aim to consolidate back with upstream once there's a release of the API stable enough
For reference:
Backward compatible changes on machine api operator:
#185
#188
#191
AWS actuator support for new group:
openshift/cluster-api-provider-aws#147

Needs:
openshift/installer#1175
Analogous PRs for Openstack/libvirt

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
To fully approve this pull request, please assign additional approvers.
We suggest the following additional approver: enxebre

If they are not already assigned, you can assign the PR to them by writing /assign @enxebre in a comment when ready.

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[openshift-ci-robot]

@enxebre: The following tests failed, say /retest to rerun them all:

Test name	Commit	Details	Rerun command
ci/jenkins/integration	4773449	link	/test integration
ci/prow/e2e-aws	4773449	link	/test e2e-aws
ci/prow/e2e-aws-operator	4773449	link	/test e2e-aws-operator
ci/prow/images	4773449	link	/test images

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[openshift-ci-robot]

@enxebre: PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[enxebre]

closing in favour of #201