Add field internal_reference to invoice addresses

src/pretix/base/migrations/0082_invoiceaddress_internal_reference.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.2 on 2017-10-26 22:13
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0081_quota_cached_availability_paid_orders'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='invoiceaddress',
+            name='internal_reference',
+            field=models.TextField(blank=True, help_text='This reference will be printed on your invoice for your convenience.', verbose_name='Internal reference'),
+        ),
+        migrations.AddField(
+            model_name='invoice',
+            name='internal_reference',
+            field=models.TextField(blank=True),
+        ),
+    ]