Add a migration for the removed ArticleSubscription model

wiki/migrations/0002_remove_article_subscription.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('django_notify', '0001_initial'),
+        ('wiki', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='articlesubscription',
+            name='articleplugin_ptr',
+        ),
+        migrations.RemoveField(
+            model_name='articlesubscription',
+            name='subscription_ptr',
+        ),
+        migrations.DeleteModel(
+            name='ArticleSubscription',
+        ),
+    ]