Fix pep8 violations in stress tests

This fixes pep8 failures that occur in the stress tests.
These included 3 types of failures: TEMPEST N301, N306, N201

Change-Id: I54211bea03430de4ad821096eaa5264afc4f22a3
diff --git a/stress/test_server_actions.py b/stress/test_server_actions.py
index 58350ac..ca66dec 100644
--- a/stress/test_server_actions.py
+++ b/stress/test_server_actions.py
@@ -17,15 +17,12 @@
 sub-class will have a corresponding PendingServerAction. These pending
 actions veriy that the API call was successful or not."""
 
-
-# system imports
 import random
 import time
 
-# local imports
-import test_case
 import pending_action
 from tempest.exceptions import Duplicate
+import test_case
 from utils.util import *