Test uploading to PyPI on release (#69)

.github/workflows/release.yml

@@ -0,0 +1,26 @@
+name: "Build and upload to PyPI"
+on:
+  release:
+    types: ["published"]
+
+jobs:
+  build:
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: "actions/checkout@v2"
+
+      - uses: "actions/setup-python@v2"
+        with:
+          python-version: "3.6"
+
+      - name: "Install packaging tools"
+        run: "python -m pip install --upgrade build twine"
+
+      - name: "Build dist package"
+        run: "python -m build"
+
+      - name: "Upload to PyPI"
+        run: "python -m twine --repository testpypi upload dist/*"
+        env:
+          TWINE_USERNAME: "__token__"
+          TWINE_PASSWORD: "${{ secrets.TESTPYPI_API_TOKEN }}"