message: updated ko version
diff: <title>Welcome to Knockout</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js"></script>
  - <script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.3.0/knockout-min.js"></script>
  + <script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-debug.js"></script>
  <!-- <link rel="stylesheet" href="https://unpkg.com/bootstrap@3.3.7/dist/css/bootstrap.min.css"> -->
  <link rel="stylesheet" href="../../packages/survey-knockout/survey.css" />
  