ci: migrate from Travis and AppVeyor to GitHub Actions

.github/workflows/push.yml

@@ -23,6 +23,7 @@ jobs:
     - name: run 'black'
       run: tox -e py37-fmt -- --check
 
+
   lin:
     strategy:
       fail-fast: false
@@ -108,3 +109,31 @@ jobs:
       run: |
         export PATH=$PATH:$(pwd)/../ghdl-v0.36/bin
         tox -e py${{ matrix.task }} -- --color=yes
+
+
+  # Deploy to PyPI whenever a release is pushed
+  # When a package version has not changed a new upload will not be triggered
+  deploy:
+    runs-on: ubuntu-latest
+    needs: [ lin, docker, win ]
+    if: github.event_name == 'release' && github.event.action == 'created'
+    steps:
+    - uses: actions/checkout@v1
+    - name: git submodule update
+      run: git submodule update --init --recursive
+    - uses: actions/setup-python@v1
+      with:
+        python-version: 3.7
+    - name: install dependencies
+      run: |
+        pip install --upgrade pip
+        pip install setuptools wheel twine
+    - name: build and deploy to PyPI
+      env:
+        TWINE_USERNAME: ${{ secrets.PYPI_USER }}
+        TWINE_PASSWORD: ${{ secrets.PYPI_PASS }}
+      run: |
+        python tools/release.py validate
+        #python setup.py sdist bdist_wheel
+        #twine upload dist/*
+        echo "This is a placeholder for deployment to PyPI"