Add AMD support.

.eslintrc

@@ -4,7 +4,8 @@
     "browser": true
   },
   "globals": {
-    "$": true
+    "$": true,
+    "define": true
   },
   "rules" : {
     "quotes": false,

src/js/adaptor/global.js

@@ -5,7 +5,13 @@
 
 var ps = require('../main');
 
-window.PerfectScrollbar = ps;
-if (typeof window.Ps === 'undefined') {
-  window.Ps = ps;
+if (typeof define === 'function' && define.amd) {
+  // AMD
+  define(ps);
+} else {
+  // Add to a global object.
+  window.PerfectScrollbar = ps;
+  if (typeof window.Ps === 'undefined') {
+    window.Ps = ps;
+  }
 }

src/js/adaptor/jquery.js

@@ -33,9 +33,14 @@ function mountJQuery(jQuery) {
   };
 }
 
-var jq = window.jQuery ? window.jQuery : window.$;
-if (typeof jq !== 'undefined') {
-  mountJQuery(jq);
+if (typeof define === 'function' && define.amd) {
+  // AMD. Register as an anonymous module.
+  define(['jquery'], mountJQuery);
+} else {
+  var jq = window.jQuery ? window.jQuery : window.$;
+  if (typeof jq !== 'undefined') {
+    mountJQuery(jq);
+  }
 }
 
 module.exports = mountJQuery;