title: Yii2 checkbox unchecked by default
body: <p>How can I render the checkbox unchecked by default?.
  I try this.</p>
  
  <pre><code>&lt;?=$form-&gt;field($model, 'rememberMe', ['template' =&gt; "&lt;div&gt;{input}&lt;/div&gt;\n&lt;div&gt;{error}&lt;/div&gt;"])-&gt;checkbox(['checked'=&gt;false])?&gt;
  </code></pre>
  
  <p>But no way. It allways appends checked="checked" to the html. I need the checkbox to be unchecked for the first time.</p>