dockerpy fails with ssh if remote machine was not added to hosts

This could be avoided by doing ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) before as mentioned on https://github.com/onyxfish/relay/issues/11#issuecomment-26494294

INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/docker/client.py", line 40, in __init__
INTERNALERROR>     self.api = APIClient(*args, **kwargs)
INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/docker/api/client.py", line 166, in __init__
INTERNALERROR>     base_url, timeout, pool_connections=num_pools
INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/docker/transport/sshconn.py", line 84, in __init__
INTERNALERROR>     self._connect()
INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/docker/transport/sshconn.py", line 94, in _connect
INTERNALERROR>     parsed.hostname, parsed.port, parsed.username,
INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/paramiko/client.py", line 416, in connect
INTERNALERROR>     self, server_hostkey_name, server_key
INTERNALERROR>   File "/root/rdo/ansible-role-container-registry/.tox/molecule/lib/python3.6/site-packages/paramiko/client.py", line 824, in missing_host_key
INTERNALERROR>     "Server {!r} not found in known_hosts".format(hostname)
INTERNALERROR> paramiko.ssh_exception.SSHException: Server 'n0' not found in known_hosts

Start in docker/transport/sshconn.py at the _connect() call shown in the traceback, and review how the Paramiko client handles hosts absent from known_hosts. Compare the proposed missing-host-key behavior with the linked discussion and verify that SSH connections to an unregistered remote host complete without the reported exception.