fix(build): fix ng build prod, lib should be coded as ES5

Author: Ghislain Beaulac

src/app/examples/grid-menu.component.ts

@@ -52,10 +52,7 @@ export class GridMenuComponent implements OnInit {
         filterable: true,
         filter: {
           collection: [{ value: '', label: '' }, { value: true, label: 'true' }, { value: false, label: 'false' }],
-          model: Filters.singleSelect,
-          filterOptions: {
-            autoDropWidth: true
-          },
+          model: Filters.singleSelect
         }
       }
     ];

src/assets/lib/multiple-select/multiple-select.js

@@ -626,7 +626,7 @@
       var scrollbarWidth = hasScrollbar ? this.getScrollbarWidth() : 0;
       var maxDropWidth = 0;
 
-      $('li span', this.$drop).each((index, elm) => {
+      $('li span', this.$drop).each(function(index, elm) {
         var spanWidth = $(elm).width();
         if (spanWidth > maxDropWidth) {
           maxDropWidth = spanWidth;