title: django countries dropdown default
body: <p>I am using Django ModelForms. I have a dropdown selector that allows users to select the country. The country is part of the booking model and is defined using  django_countries. For example,</p>
  
  <p>In models.py</p>
  
  <pre><code>from django_countries import CountryField
  
  class Booking(models.Model)
      name = models.charField(max_length=100)
      country = CountryField()
  </code></pre>
  
  <p>In views.py I want to be able to set a default selected item in the drop down menu, for example 'United Kingdom'. I know how to do this with text fields, however cannot get it to work with the CountryField(). For example,</p>
  
  <pre><code>booking = BookingForm(initial={'name': 'mr majeika'}) //works
  booking = BookingForm(initial={'country': 'United Kingdom'}) //does not work
  </code></pre>
  
  <p>I was hoping someone out there may be able to point me in the right direction? </p>