Add require imports

Author: francoispluchino

js/scroller.js

@@ -14,6 +14,7 @@ import {validateOptions} from "./utils/options";
 import {onScrolling, onPreventMouseScroll} from "./utils/events";
 import {getNativeScrollWidth, generateScrollbar} from "./utils/scrollbar";
 import {changeTranslate} from "./utils/css";
+import $ from 'jquery';
 
 /**
  * Vertical scrollbar direction.

js/sticky-header.js

@@ -10,6 +10,7 @@
 import pluginify from '@fxp/jquery-pluginify';
 import BasePlugin from '@fxp/jquery-pluginify/js/plugin';
 import {applyStickyBackgroundColor} from "./utils/sticky";
+import $ from 'jquery';
 
 /**
  * Sticky Header class.