Add github action to build and deploy to pypi

* on push to develop branch, build, but don't deploy,
* on tag push, build and deploy

.github/workflows/publish-to-pypi.yml

@@ -0,0 +1,35 @@
+name: "Publish to PyPI"
+
+on:
+  push:
+    branches:
+      - 'develop'
+    tags:
+      - '*'
+
+jobs:
+  build-and-publish:
+    name: Build and publish Python distributions to PyPI
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+
+      - name: Install pypa/build
+        run: |
+          python -m pip install --upgrade pip wheel
+          pip install build
+          pip list
+
+      - name: Build a binary wheel and a source tarball
+        run: python -m build
+
+      - name: Publish distribution to PyPI
+        if: startsWith(github.ref, 'refs/tags')
+        uses: pypa/gh-action-pypi-publish@master
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools >= 47.0.0", "wheel"]
+requires = ["setuptools ~= 60.5", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [tool.pytest.ini_options]