Add Github workflow for PyPI release. (#50)

* Add Github workflow for PyPI release.

* Clean up workflow.

* Document changes in whatsnew.

.github/workflows/pypi.yaml

@@ -0,0 +1,25 @@
+name: PyPI
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.x'
+      - name: Build distributions
+        run: |
+          python -m pip install --upgrade build
+          python -m build
+      - name: Publish on PyPI
+        uses: pypa/gh-action-pypi-publish@v1
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_API_TOKEN }}

doc/whatsnew.rst

@@ -45,6 +45,7 @@ Internal changes
 - Add very simple tests for all plot methods (:issue:`37`, pull:`49`).
 - Compute code coverage and upload to codecov.io (:issue:`38`, pull:`47`).
 - Add docs, tests and codecov badges in readme file (:pull:`48`).
+- Add automatic delivery on PyPI (:issue:`39`, :pull:`50`).
 
 .. _v0.2.1: