missing slug migration

src/c3nav/mapdata/migrations/0018_auto_20170708_1752.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.2 on 2017-07-08 15:52
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0017_point_to_poi'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='locationslug',
+            name='slug',
+            field=models.SlugField(blank=True, null=True, unique=True, verbose_name='Slug'),
+        ),
+    ]