Add a Requires on openssh-clients
    
    Generally when you have `ansible` you really want the real `ssh`, otherwise
    it may fall back to paramiko which doesn't work in a whole lot of scenarios.
    
    Specifically I was trying to use this inside a container for libostree
    testing and it took me quite a while to debug this missing dep:
    https://github.com/ostreedev/ostree/pull/1462#issuecomment-369048441