title: django crispy forms label override not working
body: <p>I can't seem to override the default label with django crispy forms.</p>
  
  <p>model.py</p>
  
  <pre><code>class User(AbstractUser):
      house_name_number = models.CharField(max_length=255)
      street_name = models.CharField(max_length=255)
      town_city = models.CharField(max_length=255)
      county = models.CharField(max_length=255)
      postcode = models.CharField(max_length=8)
      same_address = models.BooleanField()  
      move_in_date = models.DateField(null=True)
  </code></pre>
  
  <p>forms.py</p>
  
  <pre><code>class AddressForm(forms.ModelForm):
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.helper = FormHelper(self)
          self.helper.label_class = 'sr-only'
          self.helper.form_tag = False
          self.helper.layout = Layout(
              PrependedText('postcode', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;', placeholder="Postcode", autofocus=""),
              PrependedText('house_name_number', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;', placeholder="Building Number or Name",
                            ),
              PrependedText('street_name', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;', placeholder="Street Name",
                            ),
              PrependedText('town_city', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;', placeholder="Town or City",
                            label="test"),
              PrependedText('county', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;', placeholder="County"),
              Field('same_address', '&lt;i class="fa fa-home"&gt;&lt;/i&gt;',
                    label="Have you lived at the property for 3 years"),
              PrependedText('move_in_date', '&lt;i class="fa fa-calendar"&gt;&lt;/i&gt;', required=False,
                            placeholder="What date did you move in to your current address"),
          )
  </code></pre>