Make reset of ssh key code conditional on being a virtual machine.
Add and use is_vm to determine if we are running on a virtual machine.

Fix #5364
Signed-off-by: Warren Usui <warren.usui@inktank.com>
Fix to ignore ssh-key checking if running on virtual machines or
if a line that reads 'sshkey: ignore' is in the yaml file.

Fix #5364
Signed-off-by: Warren Usui <warren.usui@inktank.com>