title: display category title in django listview
body: <p>Wish to display category title in each blog category index page, using django class based listview. What I want to do is to show each category.title in each selected category page. But nothing is shown. Below is the model, view, template and it must be something small I am missing.</p>
  
  <pre><code># models.py
  class Category(models.Model):
      title = models.CharField(_('name'), max_length=100,)  
      slug = models.SlugField(_('url'), max_length=250, unique=True)
      summary = models.TextField(_('summary'), max_length=255)   
  
  class Post(models.Model):
      category = models.ForeignKey(Category))
      title = models.CharField(_('title'), max_length=255)
      slug = models.SlugField(_('url'), max_length=250, unique=True)
      content= models.TextField(_('summary'), null=True)
  
  # view.py
  class PostCategoryMixin(object):
      def get_context_data(self, **kwargs):
          context = super(PostCategoryMixin, self).get_context_data(**kwargs)
          context['category'] = Category.objects.filter(is_public=True)
          return context        
  
  class PostList(PostCategoryMixin, ListView):  
      model = Post
      queryset = Post.objects.filter(is_public=True)
      template_name = 'post/post_list.html' 
  
  class PostCategoryView(BlogCategoryMixin, ListView):
      template_name = 'post/post_list.html' 
      model = Post
      def get_queryset(self):
          return Post.objects.filter(category__slug=self.kwargs.get('slug')).filter(is_public=True) 
  
  # post_list.html
  {{ category_title }}
  </code></pre>
  
  <p>Above template tag does not fire any at all, what do I look into to display category title in the selected category page (ex, if 'software' category is selected, I wish to show 'software' as the page title.</p>