avoids potential ssh key conflicts
avoids potential ssh key conflicts

Provides better default ssh config by using
workaround from
https://github.com/ansible/ansible/issues/9442#issuecomment-221636509
- low enough control persist to avoid hijacking
- avoid use of local caches keys to avoid conflicts
- avoids poluting local host keys

RHOSINFRA-60

Change-Id: I3c36daf3b5c11da250d8f525ce197d95226adeba

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared,okolisny/InfraRed,okolisny/InfraRed,okolisny/InfraRed