chore: use `blue` code formatter, drop 3.6 + cleanup (#25) #40

	name: tests

	on:
	# Trigger the tests workflow on push or pull requests.
	push:
	branches:
	- "*"
	pull_request:
	branches:
	- master

	jobs:
	run_tox:
	name: tox -e ${{ matrix.toxenv }} (${{matrix.python-version}} on ${{ matrix.os }})
	runs-on: ${{ matrix.os }}
	strategy:
	fail-fast: false
	matrix:
	python-version:
	- "3.8"
	os:
	- "ubuntu-20.04"
	toxenv:
	- "blue"
	- "pep8"
	include:
	- python-version: "3.7"
	os: ubuntu-22.04
	toxenv: py37
	- python-version: "3.8"
	os: ubuntu-22.04
	toxenv: py38
	- python-version: "3.9"
	os: ubuntu-22.04
	toxenv: py39
	- python-version: "3.10"
	os: ubuntu-22.04
	toxenv: py310
	- python-version: "3.11"
	os: ubuntu-22.04
	toxenv: py311
	- python-version: "3.12.0-alpha - 3.12"
	os: ubuntu-22.04
	toxenv: py312
	- python-version: "pypy3.9"
	os: ubuntu-22.04
	# NOTE(vytas): do not trace coverage under PyPy, it seems it is
	# extremely expensive on PyPy 3.9 under extensive threading.
	toxenv: nocover

	# Steps to run in each job.
	# Some are GitHub actions, others run shell commands.
	steps:
	- name: Checkout repo
	uses: actions/checkout@v2

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}

	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install coverage tox
	python --version
	pip --version
	tox --version
	coverage --version

	- name: Run tests
	run: \|
	tox -e ${{ matrix.toxenv }}

	- name: Upload coverage to Codecov
	uses: codecov/codecov-action@v1
	if: ${{ matrix.toxenv == 'py38' }}
	with:
	env_vars: PYTHON
	fail_ci_if_error: true

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