Use flake8-import-order plugin

In reviews we usually check import grouping but it is boring.
By using flake8-import-order plugin, we can avoid this.
It enforces loose checking so it sounds good to use it.
This flake8 plugin is already used in tempest.

Note that flake8-import-order version is pinned to avoid unexpected
breakage of pep8 job.

Setup for unit tests of hacking rules is tweaked to disable
flake8-import-order checks. This extension assumes an actual file
exists and causes hacking rule unit tests.

Change-Id: I61e683ab0119e4ae90b7107f0690528d789e3875

neutronclient/neutron/v2_0/auto_allocated_topology.py

@@ -17,6 +17,7 @@
 from __future__ import print_function
 
 import argparse
+
 from cliff import show
 from oslo_serialization import jsonutils
 

neutronclient/tests/unit/osc/v2/fakes.py

@@ -12,9 +12,9 @@
 #
 
 import argparse
-import mock
 
 from cliff import columns as cliff_columns
+import mock
 from osc_lib.tests import utils
 
 

neutronclient/tests/unit/osc/v2/fwaas/fakes.py

@@ -16,9 +16,10 @@
 
 import collections
 import copy
-import mock
 import uuid
 
+import mock
+
 
 class FakeFWaaS(object):
 

neutronclient/tests/unit/osc/v2/fwaas/test_firewallgroup.py

@@ -15,9 +15,9 @@
 #
 
 import copy
-import mock
 import re
 
+import mock
 from osc_lib import exceptions
 from osc_lib.tests import utils
 

neutronclient/tests/unit/osc/v2/fwaas/test_firewallpolicy.py

@@ -15,9 +15,9 @@
 #
 
 import copy
-import mock
 import re
 
+import mock
 from osc_lib import exceptions
 from osc_lib.tests import utils
 

neutronclient/tests/unit/osc/v2/fwaas/test_firewallrule.py

@@ -15,12 +15,12 @@
 #
 
 import copy
-import mock
 import re
-import testtools
 
+import mock
 from osc_lib import exceptions
 from osc_lib.tests import utils
+import testtools
 
 from neutronclient.osc import utils as osc_utils
 from neutronclient.osc.v2.fwaas import constants as const

neutronclient/tests/unit/osc/v2/networking_bgpvpn/fakes.py

@@ -15,6 +15,7 @@
 #
 
 import copy
+
 import mock
 
 from neutronclient.osc import utils as nc_osc_utils

neutronclient/tests/unit/osc/v2/networking_bgpvpn/test_bgpvpn.py

@@ -15,9 +15,9 @@
 #
 
 import copy
-import mock
 import operator
 
+import mock
 from osc_lib import exceptions
 from osc_lib import utils as osc_utils
 

neutronclient/tests/unit/osc/v2/networking_bgpvpn/test_resource_association.py

@@ -15,9 +15,9 @@
 #
 
 import copy
-import mock
 import operator
 
+import mock
 from osc_lib import exceptions
 from osc_lib import utils as osc_utils
 

neutronclient/tests/unit/osc/v2/trunk/fakes.py

@@ -11,9 +11,10 @@
 #   under the License.
 
 import copy
-import mock
 import uuid
 
+import mock
+
 
 class FakeTrunk(object):
     """Fake one or more trunks."""

neutronclient/tests/unit/osc/v2/trunk/test_network_trunk.py

@@ -15,13 +15,13 @@
 
 import argparse
 import copy
+
 import mock
 from mock import call
-import testtools
-
 from osc_lib.cli import format_columns
 from osc_lib import exceptions
 from osc_lib.tests import utils as tests_utils
+import testtools
 
 from neutronclient.osc.v2.trunk import network_trunk as trunk
 from neutronclient.osc.v2 import utils as v2_utils

test-requirements.txt

@@ -5,6 +5,7 @@ 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
 mox3!=0.19.0,>=0.7.0 # Apache-2.0
 mock>=2.0 # BSD
 openstackdocstheme>=1.11.0 # Apache-2.0

tox.ini

@@ -55,5 +55,7 @@ commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenote
 [flake8]
 show-source = true
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,tools
+import-order-style = pep8
+
 # H904: Delay string interpolations at logging calls
 enable-extensions=H904