ssh_pw: New code to handle stale key in known_hosts.
ssh_pw: New code to handle stale key in known_hosts.

If the ssh results in this...

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
...
Offending RSA key in <your home>/.ssh/known_hosts:<line num>
...

The code will now delete the offending key and retry the ssh.

Change-Id: I36bab241cb6a84cdca72e53813ddd6f2f02248fe
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation