Add build step

Author: timvink

.github/workflows/pythonpublish.yml

@@ -26,6 +26,9 @@ jobs:
         pip install -r tests/test_requirements.txt
         pip install .
         pytest
+    - name: Build package
+      run: |
+        python setup.py sdist bdist_wheel
     # See https://docs.pypi.org/trusted-publishers/using-a-publisher/
     - name: Publish package distributions to PyPI
       uses: pypa/gh-action-pypi-publish@release/v1