Fix pep8 issue

Change-Id: I042740de3523262c350f687d9fe0d61710ae4fa5
diff --git a/ironic_tempest_plugin/tests/scenario/introspection_manager.py b/ironic_tempest_plugin/tests/scenario/introspection_manager.py
index 4a4dcef..988ab81 100644
--- a/ironic_tempest_plugin/tests/scenario/introspection_manager.py
+++ b/ironic_tempest_plugin/tests/scenario/introspection_manager.py
@@ -13,6 +13,7 @@
 import json
 import os
 import time
+
 import six
 import tempest
 from tempest import config