Performs the REST API Call
        :param method: HTTP Method
        :param url:  The URL
        :param json_params: The parameters intended to be JSON serialized
        :return:

def _make_api_call(self, method, url, json_params=None):
        """
        Performs the REST API Call
        :param method: HTTP Method
        :param url:  The URL
        :param json_params: The parameters intended to be JSON serialized
        :return:
        """
        if self.verbose is True:
            print "\ncrossbarhttp: Request: %s %s" % (method, url)

        if json_params is not None:
            encoded_params = json.dumps(json_params)
            headers = {'Content-Type': 'application/json'}
        else:
            encoded_params = None
            headers = {}

        if encoded_params is not None and self.verbose is True:
            print "crossbarhttp: Params: " + encoded_params

        if self.key is not None and self.secret is not None and encoded_params is not None:
            signature, nonce, timestamp = self._compute_signature(encoded_params)
            params = urllib.urlencode({
                "timestamp": timestamp,
                "seq": str(self.sequence),
                "nonce": nonce,
                "signature": signature,
                "key": self.key
            })
            if self.verbose is True:
                print "crossbarhttp: Signature Params: " + params
            url += "?" + params

        # TODO: I can't figure out what this is.  Guessing it is a number you increment on every call
        self.sequence += 1

        try:
            request = urllib2.Request(url, encoded_params, headers)
            request.get_method = lambda: method
            response = urllib2.urlopen(request).read()
            if self.verbose is True:
                print "crossbarhttp: Response: " + response

            return json.loads(response)

        except urllib2.HTTPError, e:
            if e.code == 400:
                raise ClientMissingParams(str(e))
            elif e.code == 401:
                raise ClientSignatureError(str(e))
            else:
                raise ClientBadUrl(str(e))
        except urllib2.URLError, e:
            raise ClientBadHost(str(e))