[Review] Reformat code

aleksis/core/__init__.py

aleksis/core/admin.py

aleksis/core/apps.py

aleksis/core/celery.py

aleksis/core/filters.py

aleksis/core/forms.py

aleksis/core/menus.py

aleksis/core/migrations/0001_initial.py

aleksis/core/migrations/0002_activity_notification.py

aleksis/core/migrations/0003_add_verbose_names.py

aleksis/core/migrations/0004_replace_user_by_person.py

aleksis/core/migrations/0009_dashboard_widget.py

aleksis/core/migrations/0011_make_primary_group_optional.py

aleksis/core/migrations/0012_announcement.py

aleksis/core/migrations/0013_extensible_model_as_default.py

aleksis/core/migrations/0014_accouncement_recipients.py

aleksis/core/migrations/0016_custom_menus.py

aleksis/core/migrations/0022_group_types.py

aleksis/core/migrations/0025_dynamic_preferences.py

aleksis/core/mixins.py