title: __init__() got an unexpected keyword argument 'attrs'
body: <p>forms.py:</p>
  <pre><code>class ImportExcelForm(Form):
      file  = forms.FileField(attrs={'class':'rounded_list',})
  </code></pre>
  <p>I'm trying to add css class to my <code>filefield</code> in forms.I am getting this error <code>&quot;__init__() got an unexpected keyword argument 'attrs'&quot;</code></p>
  <p>What did I do wrong?</p>
  <p>Thanks.</p>