Rework CI so it uses a matrix

.github/workflows/main.yml

@@ -8,33 +8,26 @@ jobs:
 
     runs-on: ubuntu-latest
 
-    steps:
-      - uses: actions/checkout@v1
-
-      - name: Set up Python 3.7
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.7
-
-      - name: Set up Python 3.8
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.8
+    strategy:
+      matrix:
+        python-version: ['3.7', '3.8', '3.9', '3.10']
 
-      - name: Set up Python 3.9
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.9
+    name: Python ${{ matrix.python-version }}
+    steps:
+      - uses: actions/checkout@v2.3.5
 
-      - name: Set up Python 3.10
-        uses: actions/setup-python@v1
+      - name: Set up Python
+        uses: actions/setup-python@v2.2.2
         with:
-          python-version: 3.10
+          python-version: ${{ matrix.python-version }}
 
-      - name: Install CI dependencies
+      - name: Update pip and install dev requirements
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements-dev.txt
 
-      - name: Run tests
+      - name: Lint
+        run: make lint
+
+      - name: Test
         run: tox

requirements-dev.txt

@@ -7,5 +7,6 @@ flake8==4.0.1
 pytest==7.1.2
 Sphinx==4.3.2
 tox==3.25.0
+tox-gh-actions==2.9.1
 twine==4.0.1
 wheel==0.37.1

tox.ini

@@ -1,18 +1,14 @@
-# Tox (https://tox.readthedocs.io/) is a tool for running tests
-# in multiple virtualenvs. This configuration file will run the
-# test suite on all supported python versions. To use it, "pip install tox"
-# and then run "tox" from this directory.
-
 [tox]
-envlist = py37,py38,py37-lint,py39,py310
-
-[testenv]
-commands = pip install -r requirements-dev.txt
-           pytest
+envlist = py37,py38,py39,py310
 
+[gh-actions]
+python =
+    3.7: py37
+    3.8: py38
+    3.9: py39
+    3.10: py310
 
-[testenv:py37-lint]
-basepython = python3.7
-commands = pip install -r requirements-dev.txt
-           black --check --target-version=py37 dennis tests
-           flake8 dennis tests
+[testenv]
+commands =
+    pip install -r requirements-dev.txt
+    {posargs:pytest tests/}