Add db index in counter

counter/migrations/0012_auto_20170515_2202.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('counter', '0011_auto_20161004_2039'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='permanency',
+            name='end',
+            field=models.DateTimeField(db_index=True, verbose_name='end date', null=True),
+        ),
+    ]