Add node-validate to cli

Add the node-validate command that triggers the validation of the 'core'
and 'standardized' driver interfaces of a given node. This will also be
used by the ironic driver on nova to validate the node driver interfaces
before deploying it.

Change-Id: I93811c9bfbfe4f7b8559fc4ce566c8d4e19a54ac
Merge "Add node-validate to cli"