title: react-router scroll to top on every transition
body: <p>I have an issue when navigating into another page, its position will remain like the page before. So it won't scroll to top automatically.
  I've also tried to use <code>window.scrollTo(0, 0)</code> on <code>onChange</code> router. I've also used <code>scrollBehavior</code> to fix this issue but it didn't work. Any suggestions about this?</p>