Fix migrations

src/documents/migrations/0014_auto_20180502_0852.py

@@ -11,7 +11,7 @@ def transcription_to_document(apps, schema_editor):
         new_ts = Transcription(line=ts.line, score=ts.score, text=ts.text)
         new_ts.document_ptr = Document.objects.create(type=DocumentType.Transcription, name="Transcription '{}'".format(ts.text))
         new_ts.save()
-        new_ts.zones.add(ts.zone)
+        new_ts.document_ptr.zones.add(ts.zone)
 
 
 class Migration(migrations.Migration):