update docs to show no longer compatible with later django

[markfilley]

The patterns modules cannot be imported, as deprecated in django 1.8

this file
C:\apps\nested-formset\demo\nested_formset_demo\urls.py

Documentation here https://docs.djangoproject.com/en/1.9/ref/urls/#patterns

I'm running django 1.11

[realPrimoh]

Wouldn't this be an easy fix by changing the urlpatterns to urlpatterns =[]?