Refactor with _.chain from lodash

	const userIds = _.uniq(_.map(getState().posts, 'userId'));
	userIds.forEach((id) => dispatch(fetchUser(id)));

can be refactored with lodash _.chain function into:

	_.chain(getState().posts)
	.map('userId')
	.uniq()
	.forEach(id => dispatch(fetchUser(id)))
	.value();