Deprecate N536 check

It is equivalent to H203. Prefer the built-in one.

Change-Id: Ieadefa42d40c574a5a9004974b1509df4e5f7150
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

HACKING.rst

@@ -15,5 +15,5 @@ Neutron Library Specific Commandments
 - [N532] Validate that LOG.warning is used instead of LOG.warn. The latter is deprecated.
 - [N534] Exception messages should be translated
 - [N535] Usage of Python eventlet module not allowed
-- [N536] Use assertIsNone/assertIsNotNone rather than assertEqual/assertIs to check None values.
+- [N536] DEPRECATED: Use assertIsNone/assertIsNotNone rather than assertEqual/assertIs to check None values.
 - [N537] Don't translate logs.

neutron_lib/hacking/checks.py

@@ -14,6 +14,7 @@
 
 import re
 
+from debtcollector import removals
 from hacking import core
 
 from neutron_lib.hacking import translation_checks
@@ -179,6 +180,7 @@ def check_no_eventlet_imports(logical_line):
         yield logical_line.index('eventlet'), msg
 
 
+@removals.remove(message='Use H203 check instead')
 @core.off_by_default
 @core.flake8ext
 def assert_equal_none(logical_line):
@@ -212,4 +214,3 @@ def factory(register):
     register(translation_checks.no_translate_logs)
     register(translation_checks.check_log_warn_deprecated)
     register(translation_checks.check_raised_localized_exceptions)
-    register(assert_equal_none)

tox.ini

@@ -108,7 +108,6 @@ extension =
   N530 = neutron_lib.hacking.checks:check_neutron_namespace_imports
   N532 = neutron_lib.hacking.translation_checks:check_log_warn_deprecated
   N534 = neutron_lib.hacking.translation_checks:check_raised_localized_exceptions
-  N536 = neutron_lib.hacking.checks:assert_equal_none
   N537 = neutron_lib.hacking.translation_checks:no_translate_logs
   # Checks specific to neutron-lib only
   N535 = neutron_lib.hacking.checks:check_no_eventlet_imports