Add github CI

.github/workflows/ci.yml

@@ -0,0 +1,19 @@
+name: CI
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python: ["3.9", "3.10", "3.11"]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Test with unittest
+        run: |
+          python -m unittest discover -p 'test_*.py'