bug 1462475: add db migration to cleanup after zones

kuma/wiki/migrations/0002_remove_document_zone.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.15 on 2018-08-06 17:16
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wiki', '0001_squashed_0036_update_locales'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='documentzone',
+            name='document',
+        ),
+        migrations.RemoveField(
+            model_name='document',
+            name='zone_subnav_local_html',
+        ),
+        migrations.DeleteModel(
+            name='DocumentZone',
+        ),
+    ]