まずは Csrf のミドルウェアは CsrfViewMiddleware だけで良い

とりあえず runserver して確認してみるとこんなエラーが出る。

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/wsgiref/handlers.py", line 85, in run
    self.result = application(self.environ, self.start_response)
  File "/usr/local/lib/python2.7/site-packages/django/contrib/staticfiles/handlers.py", line 72, in __call__
    return self.application(environ, start_response)
  File "/usr/local/lib/python2.7/site-packages/django/core/handlers/wsgi.py", line 236, in __call__
    self.load_middleware()
  File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 57, in load_middleware
    raise exceptions.ImproperlyConfigured('Middleware module "%s" does not define a "%s" class' % (mw_module, mw_classname))
ImproperlyConfigured: Middleware module "django.middleware.csrf" does not define a "CsrfResponseMiddleware" class

で、ドキュメントにはこんな話が。

• Cross Site Request Forgery protection

自分の setting.py には 2行入ってるぞ…。

    'django.middleware.csrf.CsrfViewMiddleware',
    'django.middleware.csrf.CsrfResponseMiddleware',

というわけで、CsrfResponseMiddleware を削除して問題解決。