TST: extend GHA test matrix to current Python versions #14

	name: Check Release
	on:
	push:
	branches: ["master"]
	pull_request:
	branches: ["*"]

	jobs:
	check_release:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	group: [check_release, link_check]
	steps:
	- name: Checkout
	uses: actions/checkout@v2
	- name: Install Python
	uses: actions/setup-python@v2
	with:
	python-version: 3.9
	architecture: "x64"
	- name: Get pip cache dir
	id: pip-cache
	run: \|
	echo "::set-output name=dir::$(pip cache dir)"
	- name: Cache pip
	uses: actions/cache@v2
	with:
	path: ${{ steps.pip-cache.outputs.dir }}
	key: ${{ runner.os }}-pip-${{ hashFiles('setup.cfg') }}
	restore-keys: \|
	${{ runner.os }}-pip-
	${{ runner.os }}-pip-
	- name: Cache checked links
	if: ${{ matrix.group == 'link_check' }}
	uses: actions/cache@v2
	with:
	path: ~/.cache/pytest-link-check
	key: ${{ runner.os }}-linkcheck-${{ hashFiles('*/.md', '*/.rst') }}-md-links
	restore-keys: \|
	${{ runner.os }}-linkcheck-
	- name: Upgrade packaging dependencies
	run: \|
	pip install --upgrade pip setuptools wheel --user
	- name: Install Dependencies
	run: \|
	pip install -e .
	- name: Check Release
	if: ${{ matrix.group == 'check_release' }}
	uses: jupyter-server/jupyter_releaser/.github/actions/check-release@v1
	with:
	token: ${{ secrets.GITHUB_TOKEN }}
	- name: Run Link Check
	if: ${{ matrix.group == 'link_check' }}
	uses: jupyter-server/jupyter_releaser/.github/actions/check-links@v1

Provide feedback