Fixes #409 dropdown does not contain easing definition for fallback js animation

src/modules/dropdown.js

@@ -836,4 +836,12 @@ $.fn.dropdown.settings = {
 
 };
 
+// Adds easing
+$.extend( $.easing, {
+  easeOutQuad: function (x, t, b, c, d) {
+    return -c *(t/=d)*(t-2) + b;
+  },
+});
+
+
 })( jQuery, window , document );