title: Update to Django 1.8 - AttributeError: django.test.TestCase has no attribute 'cls_atomics'
body: <p>I updated a Django 1.7 project to Django 1.8 and now get errors when I run the tests (that are subclasses of <code>django.test.TestCase</code>).</p>
  
  <pre><code>Traceback (most recent call last):
    File "env\lib\site-packages\django\test\testcases.py", line 962, in tearDownClass
  cls._rollback_atomics(cls.cls_atomics)
    AttributeError: type object 'SomeTests' has no attribute 'cls_atomics'
  </code></pre>
  
  <p>If I debug through the test I can step through all lines without problems, but after the last line the exception is thrown.</p>
  
  <p>This is an example test:</p>
  
  <pre><code>import django
  import unittest
  from django.test import TestCase
  import logging
  import sys
  from builtins import classmethod, isinstance
  
  class ATestTests(TestCase):
  
      @classmethod
      def setUpClass(cls):
          django.setup()
          logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
  
  
      def setUp(self):
          self._app = Application(name="a")
  
  
      def testtest(self):
  
          self.assertIsNotNone(self._app)
  </code></pre>
  
  <p>My environment:</p>
  
  <pre><code>astroid==1.3.4
  colorama==0.3.3
  defusedxml==0.4.1
  Django==1.8
  django-extensions==1.5.2
  django-filter==0.9.2
  djangorestframework==3.0.5
  djangorestframework-xml==1.0.1
  eight==0.3.0
  future==0.11.4
  logilab-common==0.63.2
  Markdown==2.5.2
  pylint==1.4.1
  python-dateutil==2.4.1
  python-mimeparse==0.1.4
  six==1.9.0
  xmltodict==0.9.2
  </code></pre>
  
  <p>How can I fix this?</p>