Update version of flake8-import-order package

Use latest version of flake8-import-order package, like we do in
openstack/ironic

Fix two issues detected by new version.

Change-Id: Idb8f0fd79c3d6b34611288f77948d042cd837806

ironic_python_agent/api/controllers/v1/__init__.py

@@ -18,7 +18,6 @@ Version 1 of the Ironic Python Agent API
 
 import pecan
 from pecan import rest
-
 from wsme import types as wtypes
 import wsmeext.pecan as wsme_pecan
 

ironic_python_agent/tests/unit/extensions/test_iscsi.py

@@ -13,9 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
-
 from ironic_lib import disk_utils
+import mock
 from oslo_concurrency import processutils
 
 from ironic_python_agent import errors

test-requirements.txt

@@ -8,7 +8,7 @@ testtools>=2.2.0 # MIT
 oslotest>=1.10.0 # Apache-2.0
 os-testr>=1.0.0 # Apache-2.0
 bashate>=0.5.1 # Apache-2.0
-flake8-import-order==0.11 # LGPLv3
+flake8-import-order>=0.13 # LGPLv3
 
 # Doc requirements
 doc8>=0.6.0 # Apache-2.0