add spanning tree #30

	name: Python package

	on:
	- push
	- pull_request

	jobs:
	build:
	strategy:
	matrix:
	platform: [ubuntu-20.04, windows-latest]
	runs-on: ${{ matrix.platform }}
	steps:
	- uses: actions/checkout@v3
	- name: Set up Python 3.6
	uses: actions/setup-python@v4
	with:
	python-version: '3.6'
	- name: Set up Python 3.8
	uses: actions/setup-python@v4
	with:
	python-version: '3.8'
	- name: Set up Python 3.10
	uses: actions/setup-python@v4
	with:
	python-version: '3.10'
	- name: Set up Python 3.12
	uses: actions/setup-python@v4
	with:
	python-version: '3.12'
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	python -m pip install tox
	- name: Test with tox
	run: python -m tox

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