Creates a new email template.

def create(self, client_id, name, html_url, zip_url):
        """Creates a new email template."""
        body = {
            "Name": name,
            "HtmlPageURL": html_url,
            "ZipFileURL": zip_url}
        response = self._post("/templates/%s.json" %
                              client_id, json.dumps(body))
        self.template_id = json_to_py(response)
        return self.template_id