Add the cli arguments to the argument parser.

def _add_cli_args(self):
        """Add the cli arguments to the argument parser."""

        # Optional cli arguments
        self._arg_parser.add_argument('-l', '--list',
                                      action='store_true',
                                      help='List installed sprockets apps')

        self._arg_parser.add_argument('-s', '--syslog',
                                      action='store_true',
                                      help='Log to syslog')

        self._arg_parser.add_argument('-v', '--verbose',
                                      action='count',
                                      help=('Verbose logging output, use -vv '
                                            'for DEBUG level logging'))

        self._arg_parser.add_argument('--version',
                                      action='version',
                                      version='sprockets v%s ' % __version__)

        # Controller sub-parser
        subparsers = self._arg_parser.add_subparsers(dest='controller',
                                                          help=DESCRIPTION)

        # Iterate through the controllers and add their cli arguments
        for key in self._controllers:
            help_text = self._get_controller_help(key)
            sub_parser = subparsers.add_parser(key, help=help_text)
            try:
                self._controllers[key].add_cli_arguments(sub_parser)
            except AttributeError:
                LOGGER.debug('%s missing add_cli_arguments()', key)

        # The application argument
        self._arg_parser.add_argument('application',
                                      action="store",
                                      help='The sprockets app to run')