Install multiple versions of Python in a single job

Author: cclauss

.github/workflows/tox.yml

@@ -7,13 +7,19 @@ jobs:
       # max-parallel: 4
       matrix:
         os: [ubuntu-latest]  # [macos-latest, ubuntu-latest, windows-latest]
-        python: ['3.7', '3.8', '3.9', '3.10', '3.11']  # '2.7' tests fail
+        # python: ['3.7', '3.8', '3.9', '3.10', '3.11']  # '2.7' tests fail
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: ${{ matrix.python }}
+          python-version: |
+            '3.7'
+            '3.8'
+            '3.9'
+            '3.10'
+            '3.11'
+          # python-version: ${{ matrix.python }}
       - run: pip install --upgrade pip
       - run: pip install tox
-      - run: tox -e py
+      - run: tox