function itemLoadingError () {
	return (dispatch) => {
		dispatch({
			type: ITEM_LOADING_ERROR,
			err: 'Network request failed',
		});
		setTimeout(() => {
			dispatch(loadItems());
		}, NETWORK_ERROR_RETRY_DELAY);
	};
}
Dispatched when unsuccessfully trying to load the items, will redispatch
loadItems after NETWORK_ERROR_RETRY_DELAY milliseconds until we get items back