See: https://core.telegram.org/bots/api#setchatphoto

def setChatPhoto(self, chat_id, photo):
        """ See: https://core.telegram.org/bots/api#setchatphoto """
        p = _strip(locals(), more=['photo'])
        return self._api_request_with_file('setChatPhoto', _rectify(p), 'photo', photo)