MAGETWO-91122: Html attributes auto removed from WYSIWYG Editor

Author: svitja

lib/web/mage/adminhtml/wysiwyg/tiny_mce/html5-schema.js

@@ -149,7 +149,8 @@ define([
             ['col', 'width align char charoff valign'],
             ['input button select textarea', 'autofocus'],
             ['input textarea', 'placeholder onselect onchange onfocus onblur'],
-            ['link script img', 'crossorigin']
+            ['link script img', 'crossorigin'],
+            ['div','aria-role'],
         ];
 
         rawData.forEach(function (data) {