Fix/eliminate warnings #1209

	# NB: this name is used in the status badge
	name: tox checks

	on:
	push:
	branches:
	- master
	- dev
	pull_request:

	workflow_dispatch:
	schedule:
	- cron: "0 5 * * 6" # 5:00 UTC every Saturday

	jobs:
	lint:
	name: ${{ matrix.toxenv }}
	runs-on: ubuntu-latest

	strategy:
	matrix:
	toxenv:
	- clean
	- check
	- docs

	steps:
	- name: Update package list
	run: sudo apt update
	- name: Install LaTeX
	run: sudo apt install dvipng rubber texlive-latex-extra
	- name: Git clone
	uses: actions/checkout@v2

	- name: Set up Python ${{ env.default_python \|\| '3.9' }}
	uses: actions/setup-python@v2
	with:
	python-version: "${{ env.default_python \|\| '3.9' }}"

	- name: Pip cache
	uses: actions/cache@v2
	with:
	path: ~/.cache/pip
	key: ${{ runner.os }}-pip-${{ matrix.toxenv }}-${{ hashFiles('tox.ini', 'setup.py') }}
	restore-keys: \|
	${{ runner.os }}-pip-${{ matrix.toxenv }}-
	${{ runner.os }}-pip-

	- name: Install dependencies
	run: \|
	python -m pip install -U pip
	python -m pip install -U setuptools wheel
	python -m pip install -U tox

	- name: Run ${{ matrix.toxenv }}
	run: python -m tox -e ${{ matrix.toxenv }}

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