Using LOG.warning replace LOG.warn


*Python 3 deprecated the logger.warn method, see:
*https://docs.python.org/3/library/logging.html#logging.warning
*so we prefer to use warning to avoid DeprecationWarning.

Change-Id: I07ee9c97c3548c965aaf83d34b37b23e9baba584
diff --git a/functional/test_aws_stack.py b/functional/test_aws_stack.py
index ba4883f..65f2ae8 100644
--- a/functional/test_aws_stack.py
+++ b/functional/test_aws_stack.py
@@ -95,7 +95,7 @@
         if key_header not in oc.head_account():
             swift_key = hashlib.sha224(
                 str(random.getrandbits(256))).hexdigest()[:32]
-            LOG.warn('setting swift key to %s' % swift_key)
+            LOG.warning('setting swift key to %s' % swift_key)
             oc.post_account({key_header: swift_key})
         key = oc.head_account()[key_header]
         path = '/v1/AUTH_%s/%s/%s' % (self.project_id,