Fix order of std and third party lib import

There are wrong import grouping of std and third party lib.
This commit fix those.

Change-Id: I15e700737776e1488167c6a392be62871b67e0b9

tempest_lib/cli/base.py

@@ -16,9 +16,10 @@
 import logging
 import os
 import shlex
-import six
 import subprocess
 
+import six
+
 from tempest_lib import base
 import tempest_lib.cli.output_parser
 from tempest_lib import exceptions

tempest_lib/tests/services/compute/base.py

@@ -13,7 +13,6 @@
 #    under the License.
 
 import httplib2
-
 from oslo_serialization import jsonutils as json
 from oslotest import mockpatch