Return the parser object for this script.

def get_parser():
    """Return the parser object for this script."""
    from argparse import ArgumentParser, ArgumentDefaultsHelpFormatter
    parser = ArgumentParser(description=__doc__,
                            formatter_class=ArgumentDefaultsHelpFormatter)
    parser.add_argument("-m", "--model",
                        dest="model",
                        help="where is the model folder (with a info.yml)?",
                        metavar="FOLDER",
                        type=lambda x: utils.is_valid_folder(parser, x),
                        default=utils.default_model())
    return parser