fix(slider): hide slider if when no hits/matches

fixes #107

Author: vvo

widgets/range-slider.js

@@ -55,8 +55,14 @@ function rangeSlider({
     },
     render({results, helper}) {
       var stats = results.getFacetStats(facetName);
+
       var currentRefinement = this._getCurrentRefinement(helper);
 
+      if (!stats) {
+        React.render(<div/>, containerNode);
+        return;
+      }
+
       React.render(
         <Slider
           start={[currentRefinement.min, currentRefinement.max]}