Hacking: enable extensions H106, H203 and H904

[H106] Don't put vim configuration in source files.
[H203] Use assertIs(Not)None to check for None.
[H904] Delay string interpolations at logging calls.

This change makes Patrole's hacking consistent with
Tempest's [0][1].

[0] https://review.openstack.org/#/c/408211/
[1] https://review.openstack.org/#/c/408066/

Change-Id: Ia56f66b4ab7e1eea6a8bfea05bf52865be13430c
diff --git a/patrole_tempest_plugin/rbac_rule_validation.py b/patrole_tempest_plugin/rbac_rule_validation.py
index d77b2d6..60a0f10 100644
--- a/patrole_tempest_plugin/rbac_rule_validation.py
+++ b/patrole_tempest_plugin/rbac_rule_validation.py
@@ -104,7 +104,7 @@
                            (role, rule))
                     LOG.error(msg)
                     raise exceptions.Forbidden(
-                        "%s exception was: %s" % (msg, e))
+                        "%s Exception was: %s" % (msg, e))
             except Exception as e:
                 exc_info = sys.exc_info()
                 error_details = exc_info[1].__str__()
@@ -115,7 +115,7 @@
                 six.reraise(exc_info[0], exc_info[0](msg), exc_info[2])
             else:
                 if not allowed:
-                    LOG.error("Role %s was allowed to perform %s" %
+                    LOG.error("Role %s was allowed to perform %s",
                               (role, rule))
                     raise rbac_exceptions.RbacOverPermission(
                         "OverPermission: Role %s was allowed to perform %s" %