Return a HTTPStatus compliant headers attribute

        FIX: duplicate headers will collide terribly!

def get_headers(self):
        """ Return a HTTPStatus compliant headers attribute

        FIX: duplicate headers will collide terribly!
        """

        headers = {'Content-Type': goldman.JSON_MIMETYPE}

        for error in self.errors:
            if 'headers' in error:
                headers.update(error['headers'])
        return headers