Multiple apps: Sort imports and minor style fixes

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/document_indexing/migrations/0013_auto_20170714_2133.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-# Generated by Django 1.10.7 on 2017-07-14 21:33
 from __future__ import unicode_literals
 
 from django.db import migrations
@@ -14,6 +12,10 @@ class Migration(migrations.Migration):
     operations = [
         migrations.AlterModelOptions(
             name='index',
-            options={'ordering': ('label',), 'verbose_name': 'Index', 'verbose_name_plural': 'Indexes'},
+            options={
+                'ordering': ('label',),
+                'verbose_name': 'Index',
+                'verbose_name_plural': 'Indexes'
+            },
         ),
     ]