Django settings improvements: also look at MIDDLEWARE and so

[reinout]

No description provided.

[coveralls]

coverage: 100.0%. remained the same
when pulling 7d5f4cc on reinout-django-settings-improvements
into 6edfff0 on master.

[reinout]

In a project I'm working on I have a django settings file with this in it:

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "whitenoise.middleware.WhiteNoiseMiddleware",
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django.middleware.clickjacking.XFrameOptionsMiddleware",
    "corsheaders.middleware.CorsMiddleware",
]

whitenoise isn't recognised as a required package, though it is. By treating MIDDLEWARE as similar to INSTALLED_APPS, fixing this was easy :-)

[gforcada]

LGTM

[reinout]

I released 2.15.