Add github action workflow to auto-publish to PyPI (#26)

Author: eriknw

.github/workflows/publish_pypi.yml

@@ -0,0 +1,31 @@
+name: Publish to PyPI
+
+on:
+  push:
+    tags:
+      - '20*'
+
+jobs:
+  build_and_deploy:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        shell: bash -l {0}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.8"
+      - name: Install build dependencies
+        run: python -m pip install setuptools wheel
+      - name: Build wheel
+        run: python setup.py sdist bdist_wheel
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@master
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_TOKEN }}