Fallback to SSH if ping fails

While trying to work out a test case and using the tempest
plugin to exercise a centos VM, I noticed it didn't ping,
when I had previously done other work to the VM. It has
SSH'ed, it might have failed, but try to SSH in case ping
fails.

Change-Id: I4e125529de4ff96c42194f91b18281a642a30018
1 file changed