fix: prevent snap back issue on mobile

If `preventDefault` isn't called touch event propogates through to mouse
event and `onSliderMouseDown` is called. This in turn calls
`forceValueFromPosition` which can regularly cause thumb to snap back
at the end of touch event.

src/components/ReactSlider/ReactSlider.jsx

@@ -433,7 +433,8 @@ class ReactSlider extends React.Component {
         this.onEnd(this.getMouseEventMap());
     };
 
-    onTouchEnd = () => {
+    onTouchEnd = e => {
+        e.preventDefault();
         this.onEnd(this.getTouchEventMap());
     };