Parse command line arguments.

def get_args():
    """Parse command line arguments."""
    parser = argparse.ArgumentParser(
        prog=__title__,
        description=__description__,
    )
    parser.add_argument(
        '--testdb', action='store_true',
        help='create and use a database with test users'
    )
    parser.add_argument(
        '-v', '--verbose', action='store_true',
        help='print a detailed log'
    )
    parser.add_argument(
        '--debug', action='store_true',
        help='print debug log'
    )
    parser.add_argument(
        '--log-sql', action='store_true',
        help='log sql transactions'
    )
    parser.add_argument(
        '-V', '--version', action='store_true',
        help='print version info and exit'
    )
    parser.add_argument(
        '--tk', action='store_true',
        help='use old tk interface'
    )
    return parser.parse_args()