title: Django unit test not modifying database
body: <p>I am creating a unit test for a view <code>PersonRemoveView</code> that simply modifies a datetime field called <code>deletion_date</code> in a model called <code>Person</code>. This field is <code>None</code> until this view is executed, then it is set to <code>timezone.now()</code></p>
  
  <p>The problem is that the value of <code>deletion_date</code> is <code>None</code> after executing the view from the unit test.</p>
  
  <p>This is the test:</p>
  
  <p><code>def test_person_remove_view(self):
      person = models.Person.objects.get(pk=1)
      request = self.factory.post('/person/remove/{}'.format(person.id))
      response = PersonRemoveView.as_view()(request, pk=person.id)
      self.assertIsNotNone(person.deletion_date)</code></p>
  
  <p>and this is the view:</p>
  
  <pre><code>class PersonRemoveView(PermissionRequiredMixin, generic.DeleteView):
      model = Person
      success_url = reverse_lazy('control:person_list')
  
     def dispatch(self, request, *args, **kwargs):
         self.object = self.get_object()
         self.object.deletion_date = timezone.now()
         self.object.save()
         return HttpResponseRedirect(self.success_url)
  </code></pre>
  
  <p>I have been debugging and the <code>dispatch</code> method is executed as expected but the temporary test database does not change and the <code>assertIsNotNone</code> method fails</p>