Setup logging format and log level.

def setup_logging(debug, logfile=None):
    '''
    Setup logging format and log level.
    '''
    if debug:
        level = logging.DEBUG
    else:
        level = logging.INFO
    if logfile is not None:
        logging.basicConfig(format="%(asctime)s %(levelname)8s %(message)s", datefmt="%H:%M:%S %Y/%m/%d", level=level, filename=logfile)
    else:
        logging.basicConfig(format="%(asctime)s %(levelname)8s %(message)s", datefmt="%H:%M:%S %Y/%m/%d", level=level)