Bump hacking to 3.0.0

The new version enables a lot of standard flake8 checks, so a few
fixes are required. W503 is disabled as it conflicts with W504
and the latter seems to be preferred nowadays.

Change-Id: I3b1e20193a2cb3d28046ad0f2008577a95aaaefd
diff --git a/ironic_tempest_plugin/services/baremetal/base.py b/ironic_tempest_plugin/services/baremetal/base.py
index 46c0a2f..3c52fcd 100644
--- a/ironic_tempest_plugin/services/baremetal/base.py
+++ b/ironic_tempest_plugin/services/baremetal/base.py
@@ -67,8 +67,9 @@
 
     def request(self, *args, **kwargs):
         resp, resp_body = super(BaremetalClient, self).request(*args, **kwargs)
-        if (BAREMETAL_MICROVERSION and
-            BAREMETAL_MICROVERSION != api_version_utils.LATEST_MICROVERSION):
+        latest_microversion = api_version_utils.LATEST_MICROVERSION
+        if (BAREMETAL_MICROVERSION
+                and BAREMETAL_MICROVERSION != latest_microversion):
             api_version_utils.assert_version_header_matches_request(
                 self.api_microversion_header_name,
                 BAREMETAL_MICROVERSION,