message: Dispatched crumb on navigate action
diff: @@ -20,6 +20,13 @@ person.renderScene = ({ id }) => <Person id={id} />;
  const store = createStore(reducer);
  +stateNavigator.onNavigate(() => {
  + store.dispatch({
  + type: "NAVIGATE",
  + payload: {crumb: stateNavigator.stateContext.crumbs.length}
  + })
  +})
  +
  stateNavigator.navigate('people');
  addNavigateHandlers(stateNavigator);
  