title: django-crispy-forms input size
body: <p>According with <a href="http://django-crispy-forms.readthedocs.org/en/latest/crispy_tag_forms.html#bootstrap3-horizontal-forms" rel="noreferrer">django-crispy-form documentation</a>, I will be able to change input width with class <code>input-small</code>. But my form always looks with width at 100%:</p>
  
  <p><img src="https://i.stack.imgur.com/6SNDw.png" alt="enter image description here"></p>
  
  <p>Also, If I add css_class to Field the size remains at width:100% ( <code>.form-control</code> )</p>
  
  <p>I have set form as documentation explains:</p>
  
  <pre><code>class LoginForm(forms.Form):
      usuari = forms.CharField( help_text = u'Codi Usuari')
      paraula_de_pas = forms.CharField( help_text = u'Paraula de pas')
  
      # Uni-form
      helper = FormHelper()
      helper.form_class = 'form-horizontal'
      helper.label_class = 'col-lg-2'  
      helper.field_class = 'col-lg-8'  
      helper.layout = Layout(
          PrependedText('usuari', 
                        '&lt;span class="glyphicon glyphicon-user"&gt;&lt;/span&gt; ',  
                        css_class='input-small'),
          PrependedText('paraula_de_pas', 
                        '&lt;span class="glyphicon glyphicon-asterisk"&gt;&lt;/span&gt; ', 
                        css_class='input-small'),
          FormActions(
              Submit('save_changes', 'Entrar-hi', css_class="btn-primary"),
          )
      )
  </code></pre>
  
  <p>In settings:</p>
  
  <pre><code>CRISPY_TEMPLATE_PACK="bootstrap3"
  </code></pre>
  
  <p>I'm up to date version. What is wrong? </p>