Add release workflow (#14)

Author: cdce8p

.github/workflows/release.yaml

@@ -0,0 +1,36 @@
+name: Release
+
+on:
+  release:
+    types:
+      - created
+
+env:
+  DEFAULT_PYTHON: 3.9
+
+jobs:
+  release-pypi:
+    name: Upload release to PyPI
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code from Github
+        uses: actions/[email protected]
+      - name: Set up Python ${{ env.DEFAULT_PYTHON }}
+        id: python
+        uses: actions/[email protected]
+        with:
+          python-version: ${{ env.DEFAULT_PYTHON }}
+      - name: Install requirements
+        run: |
+          python -m pip install -U pip setuptools twine wheel
+      - name: Build distributions
+        run: |
+          python setup.py sdist bdist_wheel
+      - name: Upload to PyPI
+        if: github.event_name == 'release' && startsWith(github.ref, 'refs/tags')
+        env:
+          TWINE_REPOSITORY: pypi
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.PYPI_API_TOKEN }}
+        run: |
+          twine upload --verbose dist/*