fileutils ut test randomly fail

[ZhiQiang Fan]

FAIL: oslo_utils.tests.test_fileutils.WriteToTempfileTestCase.test_file_with_not_existing_path_and_not_default_suffix
tags: worker-10
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Empty attachments:
  stderr
  stdout

Traceback (most recent call last):
  File "oslo_utils/tests/test_fileutils.py", line 177, in test_file_with_not_existing_path_and_not_default_suffix
    shutil.rmtree('/tmp/testing')
  File "/usr/lib/python2.7/shutil.py", line 252, in rmtree
    onerror(os.remove, fullname, sys.exc_info())
  File "/usr/lib/python2.7/shutil.py", line 250, in rmtree
    os.remove(fullname)
OSError: [Errno 2] No such file or directory: '/tmp/testing/test2'
Ran 8355 tests in 5.018s (+0.169s)
FAILED (id=17, failures=1 (+1))
error: testr failed (1)

[Davanum Srinivas (DIMS) (dims-v)]

This issue was fixed in the openstack/oslo.utils 3.3.0 release.

[ChangBo Guo(gcb) (glongwave)]

Fix Proposed in https://review.openstack.org/#/c/257903/