This patch and "Sample script for deploying k8s with kubespray"
are actually the same one. For the convenience of review, they
were submitted separately.
This patch is only about the content of scale k8s nodes. Since
the content of `NodePort` is not involved when scaling CNF,
there is no need to modify the configuration of Load Balancer.
The type of input parameter `additionalParams` of
ScaleVnfRequest is `DictOfStringsField`. The type of Kubernetes
cluster parameters used in MgmtDriver is dict, `DictOfStringsField`
type cannot adapt it. So we modify the type of additionalParams to
`DictOfNullableField`.
Implements: blueprint k8s-mgmtdriver-kubespray
Change-Id: Ib5e009c53dd834624d91ea38c9facba832d65d2b