Validate `add_policy_tag` command.

https://tickets.puppetlabs.com/browse/RAZOR-178
Validate `remove_policy_tag` command.

https://tickets.puppetlabs.com/browse/RAZOR-178
Validate `modify_policy_max_count` command.

https://tickets.puppetlabs.com/browse/RAZOR-178
Validate `update_node_metadata` command.

https://tickets.puppetlabs.com/browse/RAZOR-178
Validate `remove_node_metadata` command.

https://tickets.puppetlabs.com/browse/RAZOR-178
Validate `modify_node_metadata` command.

https://tickets.puppetlabs.com/browse/RAZOR-178