title: Vue.js cannot get the new value of radio button
body: <p>I am using vue.js as the front end framework of a page that is using pug, I tried to change the value of the radio button if the select is changed. The change in the value is successful but vue.js cannot get the new value. Here is the form: </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>script.
    $(document).ready(function (){
      $('#month').change(function (){
        $('#trial').val('SDFSDFA');
      });
    });</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>#monthly.col-sm-12
    .col-sm-12
      select#month.form-control(v-model='selected')
        option(disabled='', value='') Please select month
        option January
        option February
        option March
        option April
        option May
        option June
        option July
        option August
        option September
        option October
        option November
        option December
      input#trial(type='radio', value='', v-model='picked')
      label(for='one') One
      br
      input#two(type='radio', value='Two', v-model='picked')
      label(for='two') Two
      br
      span Picked: {{ picked }}</code></pre>
  </div>
  </div>
  </p>