Add GitHub Action

Adds GitHub Action to the Python library that will automate
building/publishing to PyPI on pushes to the master branch.

Author: Brett Mortensen

.github/workflows/publish.yml

@@ -0,0 +1,23 @@
+name: Publish
+
+on:
+  push:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+      - name: Install build
+        run: python -m pip install build
+      - name: Build dist files
+        run: python -m build
+      - name: Publish a Python distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          user: __token__
+          password: ${{ secrets.PYPI_API_TOKEN }}