refactor(sortable.e2e.multi.spec): proper clean-up DOM elements

Author: thgreasi

test/sortable.e2e.multi.spec.js

@@ -98,8 +98,8 @@ describe('uiSortable', function() {
         expect(itemsTop).toEqual(listContent(elementTop));
         expect(itemsBottom).toEqual(listContent(elementBottom));
 
-        $(elementTop).remove();
-        $(elementBottom).remove();
+        $(wrapperBottom).remove();
+        $(wrapperTop).remove();
       });
     });