Add CI

.github/worflows/main.yml

@@ -0,0 +1,26 @@
+name: Python CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["2.7", "3.6", "3.7", "3.8", "3.9"]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v3
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+      - name: Display Python version
+        run: python -c "import sys; print(sys.version)"
+      - name: Run tests
+        run: |
+          python3 -m unittest tests