Use method ensure_tree from oslo.utils

Oslo.utils provides same function and just use it.

Change-Id: Iac245d4d98c41edea5294a4d8842db69a42b3794

taskflow/persistence/backends/impl_dir.py

@@ -24,6 +24,7 @@ import shutil
 import cachetools
 import fasteners
 from oslo_serialization import jsonutils
+from oslo_utils import fileutils
 
 from taskflow import exceptions as exc
 from taskflow.persistence import path_based
@@ -146,7 +147,7 @@ class Connection(path_based.PathBasedConnection):
 
     def _ensure_path(self, path):
         with _storagefailure_wrapper():
-            misc.ensure_tree(path)
+            fileutils.ensure_tree(path)
 
     def _create_link(self, src_path, dest_path, transaction):
         with _storagefailure_wrapper():

taskflow/utils/misc.py

@@ -18,7 +18,6 @@
 import collections
 import contextlib
 import datetime
-import errno
 import inspect
 import os
 import re
@@ -467,24 +466,6 @@ def as_int(obj, quiet=False):
     return obj
 
 
-# Taken from oslo-incubator file-utils but since that module pulls in a large
-# amount of other files it does not seem so useful to include that full
-# module just for this function.
-def ensure_tree(path):
-    """Create a directory (and any ancestor directories required).
-
-    :param path: Directory to create
-    """
-    try:
-        os.makedirs(path)
-    except OSError as e:
-        if e.errno == errno.EEXIST:
-            if not os.path.isdir(path):
-                raise
-        else:
-            raise
-
-
 @contextlib.contextmanager
 def capture_failure():
     """Captures the occurring exception and provides a failure object back.