Install the package in the ci workflow

.github/workflows/python-package.yml

@@ -28,6 +28,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install -r requirements-dev.txt
+        python -m pip install .
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names