Ask Yahoo! who is the woeid from GPS position.

def get_woeid(lat, lon):
    """Ask Yahoo! who is the woeid from GPS position."""
    yql = _YQL_WOEID.format(lat, lon)

    # send request
    tmpData = _yql_query(yql)

    if tmpData is None:
        _LOGGER.error("No woid is received!")
        return None

    # found woid?
    return tmpData.get("place", {}).get("woeid", None)