Tempest: add auto-discovery test

Add test, which delete pre-created baremetal vms, and discovers it
via 'enroll' not_found_hook with default configuration.

Note, test contains workaround for working on infra, as infra 'tempest'
user doesn't have access to virsh, for running node and whitelisting
firewall rules on existing node, inspector's inspect api is used.

Change-Id: Ib0ec63295a496229b27552cd1bcf7e763c0c3e03
4 files changed