Work around a bug in FlatList

More or less the same as meliorence/react-native-snap-carousel@24731a0

Author: infostreams

src/libraries/ViewPager/index.js

@@ -108,6 +108,14 @@ export default class ViewPager extends PureComponent {
 
         const finalX = this.getScrollOffsetOfPage(page);
         this.scroller.startScroll(this.scroller.getCurrX(), 0, finalX - this.scroller.getCurrX(), 0, 0);
+        
+        requestAnimationFrame(() => {
+            // this is here to work around a bug in FlatList, as discussed here
+            // https://github.com/facebook/react-native/issues/1831
+            // (and solved here https://github.com/facebook/react-native/commit/03ae65bc ?)
+            this.scrollByOffset(1);
+            this.scrollByOffset(-1);
+        });
     }
 
     componentDidUpdate (prevProps) {