Allow payment providers to supply invoice content

src/pretix/base/migrations/0037_invoice_payment_provider_text.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.9 on 2016-09-06 21:31
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0036_auto_20160902_0755'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='invoice',
+            name='payment_provider_text',
+            field=models.TextField(blank=True),
+        ),
+    ]