Upgrade Paramiko - Python SSH library to >= 1.16

Most VMs in production have security restrictions. SSH is allowed only using modern and strong MAC (Message Authentication Code) algorithms.

Current paramiko 1.13 does not support these MACs. When you try to execute an SSH to a harden server you will get:

{"result": "Failed to run action [action_ex_id=None, action_cls='<class 'mistral.actions.action_factory.SSHAction'>', attributes='{}', params='{u'username': u'root', u'cmd': u'hostname', u'host': u'10.1.1.100', u'password': u'secret', u'private_key_filename': None}']\n Failed to execute ssh cmd 'hostname' on [u'localhost']\nException: Incompatible ssh server (no acceptable macs)"}

paramiko 1.16 supports these new MACs (https://raw.githubusercontent.com/paramiko/paramiko/1.16/sites/www/changelog.rst)