Update cache information for url

        :param url: Update for this url
        :type url: str | unicode
        :param cache_info: Cache info
        :type cache_info: floscraper.models.CacheInfo
        :rtype: None

def update(self, url, cache_info=None):
        """
        Update cache information for url

        :param url: Update for this url
        :type url: str | unicode
        :param cache_info: Cache info
        :type cache_info: floscraper.models.CacheInfo
        :rtype: None
        """
        key = hashlib.md5(url).hexdigest()
        access_time = None
        if not cache_info:
            cache_info = CacheInfo()
        if not access_time:
            cache_info.access_time = now_utc()
        self._cache_meta_set(key, cache_info.to_dict())