Add matrix of Python versions

.github/workflows/lint-test-cov.yml

@@ -16,19 +16,25 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [ '3.8', '3.9', '3.10' ]
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python 3.10
+
+    - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v3
       with:
-        python-version: "3.10"
+        python-version: ${{ matrix.python-version }}
+
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
         pip install flake8 pytest pytest-flake8 pytest-cov
         pip install -r requirements-dev.txt
         pip install -e .
+
     - name: Testing and coverage with pytest
       run: |
         pytest