add github workflow

.github/workflows/python-test.yml

@@ -0,0 +1,28 @@
+name: PyOthello
+
+on:
+  push:
+    branches: ["master"]
+  pull_request:
+    branches: ["master"]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: ["3.11"]
+
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v3
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Run tests
+        run: |
+          pytest