iamnnort/How to mimic componentDidUpdate() with React Hooks

## How to mimic componentDidUpdate() with React Hooks
const App = props => {
  const didMountRef = useRef(false)
  useEffect(() => {
    if (didMountRef.current) {
      doStuff()
    } else didMountRef.current = true
  }
}
	const App = props => {
	const didMountRef = useRef(false)
	useEffect(() => {
	if (didMountRef.current) {
	doStuff()
	} else didMountRef.current = true
	}
	}