Sonar qube 3 (#166)

* add unittests for mqtt.py

* add mock

* move test requirements into a file

* fix unit tests

* fix formating

* initial version

* fix SonarQube warning

.github/workflows/python-app.yml

@@ -36,6 +36,15 @@ jobs:
         timezoneLinux: "Europe/Berlin"
         timezoneMacos: "Europe/Berlin"
         timezoneWindows: "Europe/Berlin"
+    # - name: Start Mosquitto
+    #  uses: namoshek/mosquitto-github-action@v1
+    #  with:
+    #    version: '1.6'
+    #    ports: '1883:1883 8883:8883'
+        # certificates: ${{ github.workspace }}/.ci/tls-certificates
+        # config: ${{ github.workspace }}/.ci/mosquitto.conf
+        # password-file: ${{ github.workspace}}/.ci/mosquitto.passwd
+    #    container-name: 'mqtt'
     - uses: actions/checkout@v4
       with:
         fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
@@ -46,7 +55,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest pytest-asyncio pytest-cov coverage
+        if [ -f requirements-test.txt ]; then pip install -r requirements-test.txt; fi
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Lint with flake8
       run: |