(add) github action workflow to release pypi

+# https://github.com/LeadingEDJE/stackmanager/blob/master/.github/workflows/release.yml
+
+name: Release to PyPI
+
+on:
+  release:
+    types: [released]
+
+jobs:
+  release:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+    - name: Install Tools
+      run: |
+        python -m pip install --upgrade pip
+        pip install setuptools wheel twine
+    - name: Package and Upload
+      env:
+        COMMIT_VERSION: ${{ github.event.release.tag_name }}
+        TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
+        TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
+      run: |
+        python setup.py sdist bdist_wheel
+        twine upload dist/*