Add a smoke test workflow of forecast.py

.github/workflows/python.yml

@@ -24,3 +24,8 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements.txt
+
+      - name: Smoke test
+        run: |
+          export PYTHONPATH=$(pwd)/lib:$PYTHONPATH
+          pytest ./tests

tests/test_forecast.py

@@ -0,0 +1,13 @@
+import sys
+import os
+import pytest
+
+
+def test_import_forecast():
+    """Test that the forecast module can be imported successfully."""
+    try:
+        import forecast
+
+        assert True, "forecast imported successfully."
+    except ImportError as e:
+        pytest.fail(f"Failed to import forecast: {e}")