don't store source images in database

src/c3nav/mapdata/migrations/0016_remove_source_image.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.2 on 2017-07-08 12:52
+from __future__ import unicode_literals
+
+import os
+
+from django.conf import settings
+from django.db import migrations
+
+
+def move_sources(apps, schema_editor):
+    Source = apps.get_model('mapdata', 'Source')
+    for source in Source.objects.all():
+        with open(os.path.join(settings.SOURCES_ROOT, source.name), 'wb') as f:
+            f.write(source.image)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0015_auto_20170706_1334'),
+    ]
+
+    operations = [
+        migrations.RunPython(move_sources),
+        migrations.RemoveField(
+            model_name='source',
+            name='image',
+        ),
+    ]