Use pyproject.toml in CI

.github/workflows/pythonpackage.yml

@@ -20,7 +20,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python setup.py install
+        python -m pip install .
     - name: Lint with flake8
       run: |
         python -m pip install flake8