Use flake8-import-order plugin

This enables the process to be automated and not rely on
review inputs.

Change-Id: Ie829b9c53dd1b251785802ecbf364e97b1437ff5

neutron_lib/api/extensions.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import abc
+
 import six
 
 from neutron_lib._i18n import _

neutron_lib/api/validators/__init__.py

@@ -11,10 +11,10 @@
 #    under the License.
 
 import collections
-import re
-
 import functools
 import inspect
+import re
+
 import netaddr
 from oslo_log import log as logging
 from oslo_utils import netutils

neutron_lib/fixture.py

@@ -11,6 +11,7 @@
 # under the License.
 
 import copy
+
 import fixtures
 import mock
 

neutron_lib/plugins/ml2/api.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import abc
+
 import six
 
 

neutron_lib/tests/_tools.py

@@ -13,10 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import fixtures
 import platform
 import warnings
 
+import fixtures
+
 from neutron_lib.utils import helpers
 
 

test-requirements.txt

@@ -6,6 +6,7 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
+flake8-import-order==0.12 # LGPLv3
 python-subunit>=0.0.18 # Apache-2.0/BSD
 sphinx>=1.6.2 # BSD
 openstackdocstheme>=1.11.0 # Apache-2.0

tox.ini

@@ -53,6 +53,7 @@ commands =
 enable-extensions=H904
 show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,tools
+import-order-style = pep8
 
 [hacking]
 import_exceptions = neutron_lib._i18n