Configures ruff as the one stop linter and resolves warnings it raised

src/documents/migrations/0010_log.py

@@ -1,6 +1,4 @@
-# -*- coding: utf-8 -*-
 # Generated by Django 1.9 on 2016-02-27 17:54
-from __future__ import unicode_literals
 
 from django.db import migrations, models
 
@@ -42,7 +40,7 @@ class Migration(migrations.Migration):
                 (
                     "component",
                     models.PositiveIntegerField(
-                        choices=[(1, "Consumer"), (2, "Mail Fetcher")]
+                        choices=[(1, "Consumer"), (2, "Mail Fetcher")],
                     ),
                 ),
                 ("created", models.DateTimeField(auto_now_add=True)),