Instantiates the argparse parser

def parser(self):
        """
        Instantiates the argparse parser
        """
        if self._parser is None:
            apkw = {
                'description': self.description,
                'epilog':      self.epilog,
            }
            self._parser = argparse.ArgumentParser(**apkw)

            # For Python 3 add version as a default command
            if self.version:
                self._parser.add_argument(
                    '-v', '--version', action='version',
                    version="%(prog)s {}".format(self.version),
                )

        return self._parser