Release workflow: automate sdist creation / GitHub release (#370)

.github/workflows/release.yml

@@ -0,0 +1,60 @@
+name: Release and publish pygeos to GitHub
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  build-n-publish:
+    name: Build and publish pygeos to GitHub
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v2
+
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.x"
+
+      - name: Build a source tarball
+        run: |
+          python -m pip install --upgrade pip
+          pip install setuptools
+          python setup.py sdist
+
+      # - name: Publish distribution to PyPI
+      #   uses: pypa/gh-action-pypi-publish@master
+      #   with:
+      #     user: __token__
+      #     password: ${{ secrets.PYPI_API_TOKEN }}
+
+      - name: Create GitHub Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by Actions, you do not need to create your own token
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: false
+          prerelease: false
+
+      - name: Get Asset name
+        run: |
+          export PKG=$(ls dist/ | grep tar)
+          set -- $PKG
+          echo "name=$1" >> $GITHUB_ENV
+
+      - name: Upload Release Asset (sdist) to GitHub
+        id: upload-release-asset 
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: dist/${{ env.name }}
+          asset_name: ${{ env.name }}
+          asset_content_type: application/zip