Add gh workflow to auto publish releases

Author: bdewilde

.github/workflows/publish_package.yml

@@ -0,0 +1,27 @@
+name: publish package
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - name: install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install setuptools wheel twine
+    - name: build and publish
+      env:
+        TWINE_REPOSITORY: pypi
+        TWINE_USERNAME: ${{ secrets.PYPI_USERNAME_BURTON }}
+        TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD_BURTON }}
+      run: |
+        python setup.py sdist bdist_wheel
+        twine upload dist/*