title: Crispy Forms: Default selected value for FieldSet
body: <p>I have a list of items that I'm populating into a crispy forms ChoiceField</p>
  
  <p>For the life of me, I can't figure out how to set which item in REGION_CHOICE is selected by default.</p>
  
  <pre><code>    REGIONS = {
         'us': 'US VALUE',
         'ch': 'CH VALUE'
      }
  
      REGION_CHOICE = list(REGIONS.items())
      region = forms.ChoiceField(label='', choices=REGION_CHOICE, required=True)
  </code></pre>
  
  <p>Layout:</p>
  
  <pre><code>    self.helper.layout = Layout(
          Field('request', placeholder='Begin with a value...'),
          Field('region'),
          Submit("SUBMIT", "SUBMIT"),
          HTML('&lt;a href="{% url \'rush\' %}" class="btn btn-primary btn-md right"&gt;rush History&lt;/a&gt;')
      )
  </code></pre>
  
  <p>How can I select a default value for my  input?</p>