This breaks my local maas install, since I'm running it on artful. After upgrade, I can't use the MaaS CLI:

 mtrudel@demeter  /srv  maas demeter                                                                                          
Traceback (most recent call last):
  File "/usr/bin/maas", line 12, in <module>
    sys.exit(maascli.main())
  File "/usr/lib/python3/dist-packages/maascli/__init__.py", line 24, in main
    parser = prepare_parser(argv)
  File "/usr/lib/python3/dist-packages/maascli/parser.py", line 70, in prepare_parser
    register_cli_commands(parser)
  File "/usr/lib/python3/dist-packages/maascli/cli.py", line 194, in register_cli_commands
    load_regiond_commands(management, parser)
  File "/usr/lib/python3/dist-packages/maascli/cli.py", line 227, in load_regiond_commands
    klass = management.load_command_class(app, name)
  File "/usr/lib/python3/dist-packages/django/core/management/__init__.py", line 40, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 697, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/usr/lib/python3/dist-packages/maasserver/management/commands/apikey.py", line 14, in <module>
    from django.contrib.auth.models import User
  File "/usr/lib/python3/dist-packages/django/contrib/auth/models.py", line 4, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "/usr/lib/python3/dist-packages/django/contrib/auth/base_user.py", line 52, in <module>
    class AbstractBaseUser(models.Model):
  File "/usr/lib/python3/dist-packages/django/contrib/auth/base_user.py", line 53, in AbstractBaseUser
    password = models.CharField(_('password'), max_length=128)
  File "/usr/lib/python3/dist-packages/django/db/models/fields/__init__.py", line 1043, in __init__
    super(CharField, self).__init__(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/django/db/models/fields/__init__.py", line 166, in __init__
    self.db_tablespace = db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
  File "/usr/lib/python3/dist-packages/django/conf/__init__.py", line 53, in __getattr__
    self._setup(name)
  File "/usr/lib/python3/dist-packages/django/conf/__init__.py", line 41, in _setup
    self._wrapped = Settings(settings_module)
  File "/usr/lib/python3/dist-packages/django/conf/__init__.py", line 97, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/usr/lib/python3/dist-packages/maasserver/djangosettings/settings.py", line 45, in <module>
    django.template.base.add_to_builtins('django.templatetags.future')
AttributeError: module 'django.template.base' has no attribute 'add_to_builtins'