clear cache after update

test/test.js

@@ -354,6 +354,7 @@ describe('Application life cycle test', function () {
     it('create room', createRoom);
     it('can send message', sendMessage);
     it('can logout', logout);
+    it('clear cache', clearCache);
 
     it('can update', async function () {
         await browser.get('about:blank');