If we are dry-running, do not attempt to fetch the /version
resource and just return the stored FakeServerVersion,
which is done when constructing the dry-run client in
upgrade/common.go#getClient().
The problem here is that during upgrade
dry-run client reactors are backed by a dynamic client
via NewClientBackedDryRunGetterFromKubeconfig() and
for GetActions there seems to be no analog to
Discovery().Serverversion() resource for a dynamic client(?).
`kubeadm upgrade plan <version>` is now supported. If no
version is supplied then the original behavior remains.
If a version is supplied there will be no pause when figuring out
versions. Kubeadm will assume the version you pass in is the latest
stable version.
Signed-off-by: Chuck Ha <ha.chuck@gmail.com>
