Update README.md #575

	# https://docs.github.com/en/free-pro-team@latest/actions/guides/building-and-testing-python

	name: slow python
	on:
	pull_request:
	# These tests are so slow that we only run them when a PR is opened/reopened
	# If an existing PR gets new commits, only the libsec tests will run (to manually trigger a full test-suite, close and reopen the github PR)
	types: [opened, reopened]

	jobs:

	unit-tests:
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	# TODO: consider cutting down on python-version/os combos for speed
	python-version: [3.6, 3.7, 3.8, 3.9, "3.10"]
	os: [ubuntu-20.04, macos-11, macos-12, windows-2019, windows-2022]
	# TODO: add ubuntu-22.04 support! Something is up with openssl for that
	# https://github.com/bitcoin-core/secp256k1/issues/542
	exclude:
	# Ubuntu 22.04 doesn't come with python 3.6 installed
	- os: ubuntu-22.04
	python-version: 3.6
	steps:
	- uses: actions/checkout@v3
	- uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	cache: 'pip'
	cache-dependency-path: '**/requirements-test.txt'
	- name: Install python dependencies
	run: \|
	pip install -r requirements-test.txt
	- name: pytest unit tests in pure python
	run: \|
	pytest -vv --durations=0 buidl/test

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