libmachine/drivers/serial.go
func (d *SerialDriver) GetSSHHostname() (string, error) {
	d.Lock()
	defer d.Unlock()
	return d.Driver.GetSSHHostname()
}
func (d *SerialDriver) GetSSHHostname() (string, error) {
	d.Lock()
	defer d.Unlock()
	return d.Driver.GetSSHHostname()
}
// GetSSHHostname returns hostname for use with ssh