Add release job (#59)

.github/workflows/publish.yml

@@ -0,0 +1,49 @@
+name: publish
+
+on:
+  push:
+    tags:
+    - '[0-9]+.[0-9]+.[0-9]+'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build a pure Python wheel and source distribution
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Install build dependencies
+      run: python -m pip install --upgrade build
+
+    - name: Build
+      run: python -m build
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: artifacts
+        path: dist/*
+        if-no-files-found: error
+
+  publish:
+    name: Publish release
+    runs-on: ubuntu-latest
+    needs:
+    - build
+
+    steps:
+    - uses: actions/download-artifact@v3
+      with:
+        name: artifacts
+        path: dist
+
+    - name: Push build artifacts to PyPI
+      uses: pypa/gh-action-pypi-publish@v1.5.0
+      with:
+        skip_existing: true
+        user: __token__
+        password: ${{ secrets.PYPI_API_TOKEN }}