Helper method to make API calls

        :param endpoint: The endpoint to make the API call to
        :param get_data: data send through GET
        :param post_data: data send through POST

def _req(self, endpoint, get_data=dict(), post_data=dict()):

        """Helper method to make API calls

        :param endpoint: The endpoint to make the API call to
        :param get_data: data send through GET
        :param post_data: data send through POST
        """

        if get_data:
            request_parameter = "{}?{}".format(endpoint, urlencode(get_data))
        else:
            request_parameter = endpoint

        try:
            encdata = urlencode(post_data, True).encode('utf-8')
            response = self.oauth.request(request_parameter, data=encdata)
            self._checkResponseForErrors(response)
        except HTTPError as e:
            raise DeviantartError(e)

        return response