title: How to add a switch toggle button to simple form in rails
body: <p>I'm using Rails 4 and Simple Form with Bootstrap.</p>
  
  <p>I want that my checkbox will not like that:</p>
  
  <pre><code>&lt;%= c.input :my_bool_field, label: false, class: "form-control" %&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/zZBgv.png" rel="noreferrer"><img src="https://i.stack.imgur.com/zZBgv.png" alt="enter image description here"></a></p>
  
  <p>but something like that (I have the CSS for that)</p>
  
  <pre><code>&lt;label class="switch switch-primary"&gt;
      &lt;input type="checkbox" /&gt;
      &lt;span&gt;&lt;/span&gt;
  &lt;/label&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/YFeQt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/YFeQt.png" alt="enter image description here"></a></p>
  
  <p>I know I can use simple_form wrappers, but I find them a little bit confusing.. Can someone help me up creating the checkbox with that styling?</p>