title: BooleanField checkbox not render correctly with crispy_forms using bootstrap
body: <p>I am using crispy_forms and FormHelper. I have a model field declared as:</p>
  
  <pre><code>active = models.BooleanField(default=True)
  </code></pre>
  
  <p>And in my ModelForm, I have tried both the following in my Layout:</p>
  
  <pre><code>    self.helper.layout = Layout(
                      ...
          InlineCheckboxes('active'),
          Field('active'),
                      ...
  </code></pre>
  
  <p>which both not providing the desired result:</p>
  
  <p>Please see <a href="http://imgur.com/sPLCjRy" rel="noreferrer">image link</a></p>
  
  <p>While using InlineCheckboxes, I do not see the checkbox and using only Field, it's not formatted correctly.</p>
  
  <p>Please help</p>