Update python_package_testing.yaml

Author: klemengit

.github/workflows/python_package_testing.yaml

@@ -19,7 +19,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install flake8 pytest
+          pip install flake8 pytest sdypy-io
           if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
       - name: Lint with flake8
         run: |