Perform an HTTP Request using base_url and parameters
        given by kwargs. 
        Results are expected to be given in JSON format
        and are parsed to python data structures.

def _http_request(self, base_url, **kwargs):
        """
        Perform an HTTP Request using base_url and parameters
        given by kwargs. 
        Results are expected to be given in JSON format
        and are parsed to python data structures.
        """

        # Build our URI
        request_params = urlencode(kwargs)
        uri = u'%s?%s&ywsid=%s&output=%s' % \
            (base_url, request_params, self._client_key, self._output)

        self.LOG.debug("_http_request() - URI: %s", uri)

        header, response = self._conn.request(uri, method='GET')

        return header, response