title: Vue.js vee-validate at least one checkbox needs be be unchecked
body: <p>I'm allowing the user to dynamically add checkboxes to a form.  The user has the option to check or not.  What's the easiest way to check that at least one box needs to stay unchecked using vee-validate?</p>
  
  <pre><code>&lt;div class="checkbox col-xs-12 form-group" 
      :class="{'has-error': errors.has('check[' + index + '][check_exclude]')}"&gt;
    &lt;div class="checkbox""&gt;
      &lt;label&gt;
          &lt;input type="checkbox" 
             v-model="item.check_exclude" 
             v-validate data-vv-rules="max_value:0" 
             data-vv-as="Check Exclude" 
             name="check_exclude" 
             :name="'check[' + index + '][check_exclude]'" 
             value="1"&gt;
      &lt;/label&gt;
      &lt;span 
        v-cloak 
        v-show="errors.has('check[' + index + '][check_exclude]')" class="help-block"&gt;
      {{ errors.first('check[' + index + '][check_exclude]') }}
          &lt;/span&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>