Add pep8 import order check

Set flake8-import-order version to 0.17.1
Full py3 compatible version.
Add all Python3 modules to stdlib list.

Change-Id: I3f8fb265842df0ea72e6dfa3eea23c934258d864

lower-constraints.txt

@@ -7,6 +7,7 @@ dulwich==0.15.0
 extras==1.0.0
 fixtures==3.0.0
 flake8==2.5.5
+flake8-import-order==0.17.1
 hacking==3.0.0
 imagesize==0.7.1
 iso8601==0.1.11

sushy_oem_idrac/tests/unit/test_manager.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import json
-import mock
 
+import mock
 from oslotest.base import BaseTestCase
 import sushy
 from sushy.resources.manager import manager

sushy_oem_idrac/tests/unit/test_root.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import json
-import mock
 
+import mock
 from oslotest.base import BaseTestCase
 from sushy import main
 

test-requirements.txt

@@ -12,6 +12,7 @@ oslotest>=3.2.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
+flake8-import-order>=0.17.1 # LGPLv3
 
 # releasenotes
 reno>=2.5.0 # Apache-2.0

tox.ini

@@ -60,6 +60,9 @@ ignore = E123,E125
 enable-extensions=H106,H203,H204,H205,H210,H904
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
+import-order-style = pep8
+application-import-names = sushy_oem_idrac
+filename = *.py
 
 [testenv:lower-constraints]
 deps =