title: jquery validation is not getting fired for checkboxes
body: <p>I have a form where I am using jQuery validation to do validation from front end side. </p>
  
  <p>Most of the validation are working as I want it to. However , for the checkboxes, the validation not working. I have the following rules and messages in my validation jquery</p>
  
  <pre><code>  $('#submitDetails').validate({
      // 1. validation rules.
      rules: {
      ......
      ......
      ......
        custom9: {
          required: true
        },
        custom10:{
            required:true
        },
        custom11: {
          required: true
        }
      },
      // 2. Validation fail messages
      messages: {
        custom9: {
          required: "You can only claim your Plush Rewards once you have received all your items found on your reciept"
        },
        custom10: {
          required: "You must agree to the terms of conditions in order to claim your Plush Rewards Prepaid Visa Gift Card"
        },
        custom11: {
          required: "You must agree to the terms of conditions in order to claim your Plush Rewards Prepaid Visa Gift Card"
        }
      ......
      ......
      ......
  </code></pre>
  
  <p>The html is</p>
  
  <pre><code>&lt;div class="ticks"&gt;
      &lt;div class="col-xs-12  tick1"&gt;
          &lt;input type="checkbox" data-label="Have you received your entire order from Plush?" name="custom9" id="custom9" value="0" class="styled myClass prettyCheckable"&gt;&lt;span class="mandatory tick1Mandatory"&gt; * &lt;/span&gt;
  
      &lt;/div&gt;
      &lt;!--&lt;div id="error_msg"&gt;&lt;/div&gt;  --&gt;
      &lt;div class="col-xs-12 tick2"&gt;
          &lt;input type="checkbox" data-label="Please tick if you would like to join our mailing list and receive special bonus offers and the latest Plush news" name="custom10" id="custom10" value="1" class="styled myClass prettyCheckable" checked&gt;
      &lt;/div&gt;
      &lt;div class="col-xs-12 tick3"&gt;
          &lt;input type="checkbox" data-label="I have read and agree to the Terms and Conditions of this promotion and understand the Plush Privacy Policy" name="custom11" id="custom11" value="0" class="styled myClass prettyCheckable"&gt;&lt;span class="mandatory tick2Mandatory"&gt; * &lt;/span&gt;
  
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>When the submit button is clicked the validations concerned with custom9-11 do not get fired. </p>