Add deploy step: publish package and release notes

Fix #6369

.github/workflows/main.yml

@@ -10,6 +10,9 @@ on:
   push:
     branches:
       - master
+    tags:
+      - "*"
+
   pull_request:
     branches:
       - master
@@ -154,3 +157,35 @@ jobs:
         flags: ${{ runner.os }}
         fail_ci_if_error: false
         name: ${{ matrix.name }}
+
+  deploy:
+    if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
+
+    runs-on: ubuntu-latest
+
+    needs: [build]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python
+      uses: actions/setup-python@v1
+      with:
+        python-version: "3.7"
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install --upgrade wheel setuptools tox
+    - name: Build package
+      run: |
+        python setup.py sdist bdist_wheel
+    - name: Publish package to PyPI
+      uses: pypa/gh-action-pypi-publish@master
+      with:
+        user: __token__
+        password: ${{ secrets.pypi_token }}
+    - name: Publish GitHub release notes
+      env:
+        GH_RELEASE_NOTES_TOKEN: ${{ secrets.release_notes }}
+      run: |
+        sudo apt-get install pandoc
+        tox -e publish-gh-release-notes