message: Prevent missing directory from failing test
  Summary: If the directory doesn't exist then don't try to remove it.
  Test Plan: all tests pass, deleted runfiles dir to ensure.
  Reviewers: #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, jakeh
  Maniphest Tasks: T17458
diff: @@ -133,6 +133,7 @@ class IPUPipelineTest(test.TestCase):
  checkpoint_dir = os.path.dirname(checkpoint_path)
  # Remove directory from any previous run
  + if os.path.isdir(checkpoint_dir):
  shutil.rmtree(checkpoint_dir)
  strategy = ipu.ipu_strategy.IPUStrategy()
  