title: How to add extra options in dropdown list in Yii2
body: <p>I have a dropdown list in my yii2 application which fetches data from database table. now i want to add an extra options to my dropdownlist with value=1 and display=admin</p>
  
  <p>my current dropdown list is :</p>
  
  <pre><code>&lt;?= Html::dropDownLIst('assign_to', null, 
                      ArrayHelper::map(PhCrmUser::findAll(['user_type' =&gt; 'executive_manager', 'status' =&gt; CrmUser::STATUS_ACTIVE]), 'id',
                         function($model, $defaultValue) {
                            return $model['first_name']." ".$model['last_name'];
                         }
                       ),
                      ['class' =&gt; 'form-control', 'prompt' =&gt; 'Assign to Manager']
                    )?&gt;
  </code></pre>
  
  <p>it displays output as </p>
  
  <pre><code>&lt;select class="form-control" name="assign_to"&gt;
  &lt;option value=""&gt;Assign to Manager&lt;/option&gt;
  &lt;option value="8"&gt;Matt Demon&lt;/option&gt;
  &lt;option value="10"&gt;Vinit Singh&lt;/option&gt;
  &lt;option value="14"&gt;dsfds sdfsdf&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>now i want to add and extra static option to my dropdownlist how to achive it in yii. my output should look like.</p>
  
  <pre><code>&lt;select class="form-control" name="assign_to"&gt;
  &lt;option value=""&gt;Assign to Manager&lt;/option&gt;
  &lt;option value="1"&gt;Admin&lt;/option&gt;
  &lt;option value="8"&gt;Matt Demon&lt;/option&gt;
  &lt;option value="10"&gt;Vinit Singh&lt;/option&gt;
  &lt;option value="14"&gt;dsfds sdfsdf&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>