This patch supports Container Update MgmtDriver in the operation
of modifying VNF in v2 API.
It provides a sample script MgmtDriver, when modifying CNF.
If the ConfigMap and Secret are updated, the Pod, Deployment,
ReplicaSet, DaemonSet will also be updated (image only).
This patch also updated the user guide for how to use Container
Update MgmtDriver, adding the usage method in v2 API.
Implements: blueprint container-update
Change-Id: Idf7aeff010f0a4329315f75a7e4574485f1f2efc
7090af0523