Fix test

Author: wesleycho

test/tinymce.spec.js

@@ -66,7 +66,7 @@ describe('uiTinymce', function () {
 
       scope.$destroy();
 
-      expect(tinymce.get('foo')).toBeUndefined();
+      expect(tinymce.get('foo')).toBeNull();
 
       done();
     });