This is a breaking change for people using the API (sorry), but is
hopefully a simple search and replace:
"k8s.io/kops/upup/pkg/api"
-> api "k8s.io/kops/pkg/apis/kops"
"k8s.io/kops/upup/pkg/api/registry"
-> "k8s.io/kops/pkg/apis/kops/registry"
This is the "correct" place for it in the k8s API infrastructure - we
are working towards a versioned API here.
We separate out the `create cluster` operation from the `update cluster`
operation. Now create cluster only creates the spec (unless you pass
--yes), and is only for new clusters.
`update cluster` works on new or existing clusters, and should be called
to apply changes.
`update` is not the best name, because it means something different in
kubectl, but I think it's a good start.