py3: Remove all `from __future__ import unicode_literals`.

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

analytics/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
 from django.conf import settings

analytics/migrations/0002_remove_huddlecount.py

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

analytics/migrations/0003_fillstate.py

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

analytics/migrations/0004_add_subgroup.py

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

analytics/migrations/0005_alter_field_size.py

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

analytics/migrations/0006_add_subgroup_to_unique_constraints.py

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

analytics/migrations/0007_remove_interval.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.10.4 on 2017-01-16 20:50
-from __future__ import unicode_literals
-
 from django.conf import settings
 from django.db import migrations
 

analytics/migrations/0008_add_count_indexes.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.10.5 on 2017-02-01 22:28
-from __future__ import unicode_literals
-
 from django.db import migrations
 
 

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
 
 

pgroonga/migrations/0001_enable.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.db import models, migrations
 from django.contrib.postgres import operations
 from django.conf import settings

zerver/migrations/0110_stream_is_in_zephyr_realm.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.11.5 on 2017-10-08 18:37
-from __future__ import unicode_literals
-
 from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
 from django.db.migrations.state import StateApps
 from django.db import connection, migrations, models

zilencer/migrations/0001_initial.py

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

zilencer/migrations/0002_remote_zulip_server.py

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

zilencer/migrations/0003_add_default_for_remotezulipserver_last_updated_field.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.10.5 on 2017-05-16 00:03
-from __future__ import unicode_literals
-
 from django.db import migrations, models
 
 

zilencer/migrations/0004_remove_deployment_model.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.11.5 on 2017-10-12 06:27
-from __future__ import unicode_literals
-
 from django.db import migrations