Use flake8-import-order

Use the flake8 plugin flake8-import-order to check import ordering. It
can do it automatically and don't need reviewers to check it.

Change-Id: Ib3fde54d8baa2c6e3567ff3f1a902de4b25f9f70

ironic_lib/disk_utils.py

@@ -18,10 +18,8 @@ import logging
 import math
 import os
 import re
-import requests
 import shlex
 import shutil
-import six
 import stat
 import tempfile
 import time
@@ -32,6 +30,8 @@ from oslo_serialization import base64
 from oslo_utils import excutils
 from oslo_utils import imageutils
 from oslo_utils import units
+import requests
+import six
 
 from ironic_lib.common.i18n import _
 from ironic_lib.common.i18n import _LE

ironic_lib/exception.py

@@ -23,10 +23,10 @@ SHOULD include dedicated exception logging.
 """
 
 import logging
-import six
 
 from oslo_config import cfg
 from oslo_utils import excutils
+import six
 
 from ironic_lib.common.i18n import _
 from ironic_lib.common.i18n import _LE

ironic_lib/tests/test_disk_utils.py

@@ -14,12 +14,12 @@
 #    under the License.
 
 import gzip
-import mock
 import os
 import shutil
 import stat
 import tempfile
 
+import mock
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_serialization import base64

test-requirements.txt

@@ -4,6 +4,7 @@
 
 coverage>=4.0 # Apache-2.0
 eventlet!=0.18.3,>=0.18.2 # MIT
+flake8-import-order==0.11 # LGPLv3
 hacking<0.12,>=0.11.0 # Apache-2.0
 mock>=2.0 # BSD
 os-testr>=0.8.0 # Apache-2.0

tox.ini

@@ -18,6 +18,7 @@ commands = ostestr {posargs}
 show-source = True
 ignore = E129
 exclude = .venv,.tox,dist,doc,*.egg,.update-venv
+import-order-style = pep8
 
 [testenv:pep8]
 commands =