Prevented some tests from writing in the CWD.

from __future__ import unicode_literals

import os

import tempfile

import warnings

from django.apps import apps

                         natural_foreign_keys=False, natural_primary_keys=False,

                         use_base_manager=False, exclude_list=[], primary_keys=''):

        new_io = six.StringIO()

        if filename:

            filename = os.path.join(tempfile.gettempdir(), filename)

        management.call_command('dumpdata', *args, **{'format': format,

                                                      'stdout': new_io,

                                                      'stderr': new_io,