Add first pytest preparement

.github/workflows/pytest.yaml

@@ -0,0 +1,25 @@
+name: Python package
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.6", "3.7", "3.8", "3.9"]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v3
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install pytest
+          pip install -r requirements.txt
+      - name: Test with pytest
+        run: |
+          pytest

toogoodtogo_ha_mqtt_bridge/tests/test_cron.py

@@ -0,0 +1,2 @@
+def test_dummy():
+    pass