Unrelated: remove unused Django boilerplate files

tests/test_project/app_add_not_null_column/admin.py

@@ -1,3 +0,0 @@
-from django.contrib import admin
-
-# Register your models here.

tests/test_project/app_add_not_null_column/tests.py

@@ -1,3 +0,0 @@
-from django.test import TestCase
-
-# Create your tests here.

tests/test_project/app_add_not_null_column/views.py

@@ -1,3 +0,0 @@
-from django.shortcuts import render
-
-# Create your views here.