Remove usage of six

Remove six-library Replace the following items with Python 3 style code.
- six.moves

Change-Id: Ied212eb0947c7441cc51193399185b4fb0f87271
diff --git a/tools/check_logs.py b/tools/check_logs.py
index de7e41d..e2a5e30 100755
--- a/tools/check_logs.py
+++ b/tools/check_logs.py
@@ -20,9 +20,9 @@
 import os
 import re
 import sys
+import urllib.request as urlreq
 
 import six
-import six.moves.urllib.request as urlreq
 import yaml
 
 # DEVSTACK_GATE_GRENADE is either unset if grenade is not running