start adding tests, linting fixes #71

	name: Lint and Test
	on: push

	jobs:
	lint:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ["3.10", "3.11", "3.12"]
	steps:
	- uses: actions/checkout@v4
	- name: Setup Graphviz
	uses: ts-graphviz/setup-graphviz@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	id: cpython3
	with:
	python-version: ${{ matrix.python-version }}
	cache: pip
	cache-dependency-path: requirements.txt
	- run: pip install -r requirements.txt
	- run: pip install black ruff pytype pytest
	# - run: ruff check .
	- name: Run pytype if not on 3.12
	run: \|
	if [[ '${{ steps.cpython3.outputs.python-version }}' == "3.12" ]]; then
	echo "pytype does not support 3.12: https://github.com/google/pytype/issues/1475"
	else
	pytype -j auto graphviz2drawio
	fi
	- uses: psf/black@stable
	with:
	options: "--check --verbose"
	- run: pytest
	- name: Run main script
	run: \|
	python3 -m graphviz2drawio test/directed/hello.gv.txt
	test -f test/directed/hello.gv.xml

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