Update hacking

This patch updates the version of hacking to be consistent with
designate.
It is required for flake8 to understand f-strings correctly.
Along with this version update, the patch fixes issues in the code found
by the new versions.

This patch also disables two flake8 plugins from tempest T110 and T111
as they are not compatible with the newer version of flake8.
They can be re-enabled once tempest updates to a newer hacking version
and fixes these issues.

Change-Id: Ia8153724e28cd0ce032d77ff08b4c35f75a1dfc8
diff --git a/tox.ini b/tox.ini
index 7a5148b..4f0539b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -100,8 +100,9 @@
   T108 = tempest.hacking.checks:no_hyphen_at_end_of_rand_name
   N322 = tempest.hacking.checks:no_mutable_default_args
   T109 = tempest.hacking.checks:no_testtools_skip_decorator
-  T110 = tempest.hacking.checks:get_resources_on_service_clients
-  T111 = tempest.hacking.checks:delete_resources_on_service_clients
+# TODO(johnsom) Re-enable these once tempest updates hacking to > 3.1.0
+#  T110 = tempest.hacking.checks:get_resources_on_service_clients
+#  T111 = tempest.hacking.checks:delete_resources_on_service_clients
   T112 = tempest.hacking.checks:dont_import_local_tempest_into_lib
   T113 = tempest.hacking.checks:dont_use_config_in_tempest_lib
   T114 = tempest.hacking.checks:use_rand_uuid_instead_of_uuid4