title: yii2 datepicker show start date greater than current date
body: <p>I want to show dates which are greater than current date
  in ValidFrom and dates greater than ValidFrom  in ValidUpto field but unable to show.I want hide previous dates in date picker.</p>
  
  <p>My code is below.</p>
  
  <pre><code> echo DatePicker::widget([
          'model' =&gt; $model,
          'attribute' =&gt; 'ValidFrom',
          'attribute2' =&gt; 'ValidUpto',
          'options' =&gt; ['placeholder' =&gt; 'valid from',
  
          ],
          'options2' =&gt; ['placeholder' =&gt; 'valid to'],
          'type' =&gt; DatePicker::TYPE_RANGE,
          'form' =&gt; $form,
  
          'pluginOptions' =&gt; [
              'format' =&gt; 'yyyy-mm-dd',
              'autoclose' =&gt; true,
          ],
  
      ]);
  </code></pre>