Retrieve a list of &devices and values.

def update_from_devices(self):
        """Retrieve a list of &devices and values."""
        # _LOGGER.warning("update from devices")
        try:
            rest = requests.get(URL_DEVICES.format(self._url))
            if rest.status_code != 200:
                _LOGGER.error("Devices returned %s", rest.status_code)
                return False
            self.devices.update_devices(rest.json())
            return True
        except requests.exceptions.ConnectionError as conn_err:
            _LOGGER.error("Could not connect: %s", conn_err)
        except Exception as err:  # pylint: disable=broad-except
            _LOGGER.error(err)