title: Input type number in HelperForm PrestaShop
body: <p>I am unable to set input type number in HelperForm PrestaShop. 
  Only text and password types are working. When set to number type, the input box disappears.</p>
  
  <pre><code>$fields_form[0]['form'] = array(
      'legend' =&gt; array(
              'title' =&gt; $this-&gt;l('Settings'),
      ),
      'input' =&gt; array(
          array(
              'type' =&gt; 'number',
              'label' =&gt; $this-&gt;l('Number Input'),
              'name' =&gt; 'NumberInput',
              'required' =&gt; true
          )
      ),
      'submit' =&gt; array(
          'title' =&gt; $this-&gt;l('Save'),
          'class' =&gt; 'btn btn-default pull-right'
      )
  );
  </code></pre>