Allow hosts to be deleted in clients

[Chris Spencer]

Allow users to delete hosts in both the python and the command line clients.

See http://craton.readthedocs.io/en/latest/cratoncli.html#craton-host-delete for information about the expected command line arguments.

cratonclient.shell.v1.hosts_shell will need to be updated to add cli client support

cratonclient.v1.hosts will need to be updated to add python client support to the Host/HostManager.

cratonclient.tests.unit.test_hosts_shell will need to be updated to add cli testing surrounding the host deletion.

cratonclient.tests.unit.test_python_hosts will need to be updated to add python client testing surrounding the host deletion.