cd: publish releases to PyPI with GA

.github/workflows/publish-release.yml

@@ -0,0 +1,33 @@
+name: release
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  pypi:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v2
+
+      - name: Set up Python ${{ matrix.python }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python }}
+
+      - name: Install pypa/build
+        run: |
+          python -m pip install build --user
+
+      - name: Build the petl package as source tarball
+        run: |
+          # python setup.py sdist
+          python -m build --sdist --outdir dist/ .
+
+      - name: Publish the package version ${{ github.event.release.tag_name }} to PyPI
+        if: startsWith(github.ref, 'refs/tags')
+        uses: pypa/gh-action-pypi-publish@master
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}
+          print_hash: true