fix tests

.github/workflows/pythonapp.yml

@@ -23,8 +23,8 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest pytest-asyncio
-        if [ -f requirements.txt ]; then pip install -r requirements.txt dev-requirements.txt; fi
+        pip install flake8 pytest pytest-asyncio pip-tools
+        if [ -f requirements.txt ]; then pip-sync requirements.txt dev-requirements.txt; fi
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names