Makefile and python cleanups.

Makefile
--------
  o Add std copyright notice header
  o Update to use repo:onf-make to support virtualenv, etc makefile targets.
  o Update help to display a static text block.  Grep for strings prefixed
    by '##' can become confused and display 'Makefile' instead of target name.

tox.ini
-------
  o Update to also support python 3.10+

Change-Id: Id8183ad03df252c81631a8c5ef4f08fe23d0ada5
diff --git a/Makefile b/Makefile
index ca1b277..3017e49 100644
--- a/Makefile
+++ b/Makefile
@@ -1,34 +1,68 @@
-# SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+# -*- makefile -*-
+## -----------------------------------------------------------------------
+# Copyright 2020-2023 Open Networking Foundation (ONF) and the ONF Contributors <support@opennetworking.org>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+# SPDX-FileCopyrightText: Copyright 2020-2023 Open Networking Foundation (ONF) and the ONF Contributors <support@opennetworking.org>
 # SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
 
-SHELL = bash -e -o pipefail
+## Boot loader
+onf-mk-abs    ?= $(abspath $(lastword $(MAKEFILE_LIST)))
+onf-mk-top    := $(dir $(onf-mk-abs))
+onf-mk-top    := $(patsubst %/,%,$(onf-mk-top))
 
-# Common set of args, set to --debug for more output
-COMMON_ARGS ?=  --debug
+include $(onf-mk-top)/makefiles/include.mk
 
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
 # change to be 'python3 -m cProfile -s cumtime' to profile a script
-PYTHON      ?= python3
+# PYTHON      ?= python3
 
 .DEFAULT_GOAL := help
 .PHONY: cggs license clean-all help
 
 # build targets
 
-cggs: ## Sync crowd groups
-	$(PYTHON) cggs.py $(COMMON_ARGS) settings.json
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+CGGS_ARGS   ?= --debug
 
-# testing targets
-test: ## run all tests
+cggs : $(venv-activate-script)
+	$(activate) && python cggs.py $(CGGS_ARGS) settings.json
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+# test : venv-activate-script
+test : $(venv-activate-script)
 	tox
 
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
 license: ## Check code for licensing with REUSE
 	reuse --root . lint
 
-clean-all: clean ## Delete virtualenv and all cached job information
-	rm -rf .tox *.pyc
-
-help: ## Print help for each target
-	@echo cggs test targets
+## -----------------------------------------------------------------------
+## Intent: Show supported targets
+## -----------------------------------------------------------------------
+help :: ## Print help for each target
 	@echo
-	@grep '^[[:alnum:]_-]*:.* ##' $(MAKEFILE_LIST) \
-    | sort | awk 'BEGIN {FS=":.* ## "}; {printf "%-25s %s\n", $$1, $$2};'
+	@echo "Usage: $(MAKE)"
+	@printf '  %-33.33s %s\n' 'cggs' 'Crowd Group Gerrit Sync'
+	@printf '  %-33.33s %s\n' 'test' 'Run all tests'
+	@printf '  %-33.33s %s\n' 'license'\
+	    'Check code for licensing with REUSE'
+
+# [EOF]