Add missing migration for wagtail.tests

It only appears in Python 3.x for some reason.

wagtail/tests/migrations/0008_auto_20141113_2125.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('tests', '0007_registerdecorator'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='pagechoosermodel',
+            name='page',
+            field=models.ForeignKey(help_text='help text', to='wagtailcore.Page'),
+            preserve_default=True,
+        ),
+        migrations.AlterField(
+            model_name='snippetchoosermodel',
+            name='advert',
+            field=models.ForeignKey(help_text='help text', to='tests.Advert'),
+            preserve_default=True,
+        ),
+    ]