Add test run to GitHub.

.github/workflows/run-tests.yml

@@ -0,0 +1,24 @@
+# .github/workflows/app.yaml
+name: PyTest
+on: push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v3
+
+      - name: Setup Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.12"
+
+      - name: Install pip
+        run: |
+          python -m venv --copies --upgrade-deps venv
+          . venv/bin/activate
+          python -m pip install --upgrade pip wheel .[dev]
+          pytest