py3: Remove all from __future__ import unicode_literals.

This was mostly used in migrations, so it's a pretty safe change.

confirmation/migrations/0001_initial.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 import django.db.models.deletion
 

confirmation/migrations/0002_realmcreationkey.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 import django.utils.timezone
 

confirmation/migrations/0003_emailchangeconfirmation.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.10.4 on 2017-01-17 09:16
-from __future__ import unicode_literals
-
 from django.db import migrations
 
 

confirmation/migrations/0004_remove_confirmationmanager.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.11.2 on 2017-07-08 04:23
-from __future__ import unicode_literals
-
 from django.db import migrations, models