Add field 'added' to documents

This field indicates when the document was added to the database

src/documents/migrations/0020_document_added.py

@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.utils.timezone
+
+
+def set_added_time_to_created_time(apps, schema_editor):
+    Document = apps.get_model("documents", "Document")
+    for doc in Document.objects.all():
+        doc.added = doc.created
+        doc.save()
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '0019_add_consumer_user'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='document',
+            name='added',
+            field=models.DateTimeField(db_index=True, default=django.utils.timezone.now, editable=False),
+        ),
+        migrations.RunPython(set_added_time_to_created_time)
+    ]