Accounted for .sender in a few places

src/documents/migrations/0011_auto_20160303_1929.py

@@ -16,4 +16,13 @@ class Migration(migrations.Migration):
             old_name='Sender',
             new_name='Correspondent',
         ),
+        migrations.AlterModelOptions(
+            name='document',
+            options={'ordering': ('correspondent', 'title')},
+        ),
+        migrations.RenameField(
+            model_name='document',
+            old_name='sender',
+            new_name='correspondent',
+        ),
     ]