Add GH Action GitHub + PyPI release automation on git version tag pushes

.github/workflows/publish-release.yml

@@ -0,0 +1,67 @@
+on:
+  push:
+    tags:
+      - "v*" # Push events to matching `v*` version srings. e.g. v1.0, v20.15.10
+
+name: Create and Publish Release
+
+jobs:
+  build:
+    name: Create and Publish Release
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@master
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+
+      - name: Install release dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install --upgrade setuptools wheel twine
+
+      - name: Get release notes
+        id: release_notes
+        run: |
+          # By default, GH Actions checkout will only fetch a single commit.
+          # For us to extract the release notes, we need to fetch the tags
+          # and tag annotations as well.
+          # https://github.com/actions/checkout/issues/290
+          git fetch --tags --force
+          TAG_NAME=${GITHUB_REF/refs\/tags\//}
+          CHANGELOG=$(git tag -l --format='%(contents)' $TAG_NAME)
+          # we have to escape all new line characters and carriage
+          # returns before passing them into set-output otherwise the
+          # body content of the release will only contain the first line
+          # https://github.com/actions/create-release/issues/38#issuecomment-640072234
+          CHANGELOG="${CHANGELOG//'%'/'%25'}"
+          CHANGELOG="${CHANGELOG//$'\n'/'%0A'}"
+          CHANGELOG="${CHANGELOG//$'\r'/'%0D'}"
+          echo "::set-output name=changelog::$CHANGELOG"
+
+      - name: Create GitHub release
+        id: create_release
+        # create-release@v1 doesn't support the body arg so we use
+        # create-release@master instead.
+        uses: actions/create-release@master
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          # To set the body arg, we fetch the changelog variable we created
+          # in the previous step. Implementation is based on
+          # the third example in https://github.com/actions/create-release/pull/11
+          body: ${{ steps.release_notes.outputs.changelog }}
+          draft: false
+          prerelease: false
+
+      - name: Build and publish to PyPI
+        env:
+          TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
+          TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
+        run: |
+          python setup.py sdist bdist_wheel
+          twine upload dist/*