Run tests across various Python and OS versions

.github/workflows/ci.yml

@@ -7,16 +7,22 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+        version:
+          - "3.8"
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
-      - name: Set up Python 3.8
+      - name: Set up Python ${{ matrix.version }}
         uses: actions/setup-python@v4
         with:
-          python-version: 3.8
+          python-version: ${{ matrix.version }}
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip
+          pip install --upgrade pip
           pip install .
       - name: Run unit tests
         run: python -m unittest discover -s src