title: Django creating a form field that's read only using widgets
body: <p>My form field looks something like the following:</p>
  
  <pre><code>class FooForm(ModelForm):
      somefield = models.CharField(
          widget=forms.TextInput(attrs={'readonly':'readonly'})
      )
  
      class Meta:
          model = Foo
  </code></pre>
  
  <p>Geting an error like the following with the code above: <strong>init</strong>() got an unexpected keyword argument 'widget'</p>
  
  <p>I thought this is a legitimate use of a form widget?</p>