title: Django Profile Update on existing profile
body: <p>I have the following signal for creating a profile when a new user registers and then sends an email to the admin informing them of the new user </p>
  
  <pre><code>@receiver(post_save, sender=User)
  def create_user_profile(sender, **kwargs):
      '''Create a profile for a new user'''
      if kwargs['created']:
          Profile.objects.create(user=kwargs['instance'])
  
  
  @receiver(post_save, sender=User)
  def notify_admin(sender, instance, created, **kwargs):
      '''Notify the administrator that a new user has been added.'''
      if created:
          subject = 'New Registration created'
          message = 'A new candidate  %s has registered with the site' % instance.email
          from_addr = 'no-reply@example.com'
          recipient_list = ('admin@example.com', )
          send_mail(subject, message, from_addr, recipient_list)
  </code></pre>
  
  <p>I am looking to also notify the admin when a profile is updated but am struggling to come up with a solution.</p>
  
  <p>Any ideas?</p>