Update document in index.

def update(self, resource, id_, updates):
        """Update document in index."""
        args = self._es_args(resource, refresh=True)
        if self._get_retry_on_conflict():
            args['retry_on_conflict'] = self._get_retry_on_conflict()

        updates.pop('_id', None)
        updates.pop('_type', None)
        self._update_parent_args(resource, args, updates)
        return self.elastic(resource).update(id=id_, body={'doc': updates}, **args)