manage command errors

[jedie]

manage.py update_docdata_order with django 1.11:

  File "django-oscar-docdata/oscar_docdata/management/commands/update_docdata_order.py", line 11, in <module>
    class Command(BaseCommand):
  File "django-oscar-docdata/oscar_docdata/management/commands/update_docdata_order.py", line 18, in Command
    ) + BaseCommand.option_list
AttributeError: type object 'BaseCommand' has no attribute 'option_list'

[jedie]

manage.py expire_docdata_orders with django 1.11:

  File "django-oscar-docdata/oscar_docdata/management/commands/expire_docdata_orders.py", line 4, in <module>
    from django.core.management.base import NoArgsCommand
ImportError: cannot import name 'NoArgsCommand'

docdata_report has the same error...

[maerteijn]

Your commits have been merged into master with #22