libmachine/drivers/serial.go
func (d *SerialDriver) GetSSHKeyPath() string {
	d.Lock()
	defer d.Unlock()
	return d.Driver.GetSSHKeyPath()
}
func (d *SerialDriver) GetSSHKeyPath() string {
	d.Lock()
	defer d.Unlock()
	return d.Driver.GetSSHKeyPath()
}
// GetSSHKeyPath returns key path for use with ssh