Add CI workflow for Python tests

.github/workflows/tests.yml

@@ -0,0 +1,40 @@
+name: Tests
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'github_dl/**/*.py'
+  pull_request:
+    branches: [main]
+    paths:
+      - 'github_dl/**/*.py'
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Python
+        uses: actions/setup-python@v4
+        # see details (matrix, python-version, python-version-file, etc.)
+        # https://github.com/actions/setup-python
+      - name: Install poetry
+        uses: abatilo/actions-poetry@v2
+
+      - name: Setup a local virtual environment (if no poetry.toml file)
+        run: |
+          poetry config virtualenvs.create true --local
+          poetry config virtualenvs.in-project true --local
+
+      - uses: actions/cache@v3
+        name: Define a cache for the virtual environment based on the dependencies lock file
+        with:
+          path: ./.venv
+          key: venv-${{ hashFiles('poetry.lock') }}
+
+      - name: Install dependencies
+        run: poetry install
+
+      - name: Run tests
+        run: poetry run pytest -v