Having trouble solving a Django test for page content

I'm currently working my way through the Django tutorial and I'm having trouble getting one of the tests from chapter 5 to pass.

Specifically this one:

    def test_detail_view_with_a_past_question(self):
        past_question = create_question(question_text='Past question.', days=-5)
        response = self.client.get(reverse('polls:detail', args=(past_question.id,)))
        self.assertContains(response, past_question.question_text, status_code=200)

I see the response does contain 'Past question'. But it's stored under response -> context_data -> 'question'

Here's the function for create question:

def create_question(question_text, days):
    time = timezone.now() + datetime.timedelta(days=days)
    return Question.objects.create(question_text=question_text, pub_date=time)

The Question model:

class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')

    def __unicode__(self):
        return self.question_text

    def was_published_recently(self):
        now = timezone.now()
        return now - datetime.timedelta(days=1) <= self.pub_date <= now

    was_published_recently.admin_order_field = 'pub_date'
    was_published_recently.boolean = True
    was_published_recently.short_description = 'Published recently?'

And the view:

class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        """
        return Question.objects.filter(pub_date__lte=timezone.now())

If it helps, the Git repo with everything can be found here.

Thanks in advance for the help!