ensure env var set

shared/data_store/put_model.py

@@ -18,6 +18,7 @@ def put_model(
     used as object name."""
     assert isinstance(client, Minio)
     assert isinstance(model, Module)
+    assert 'MINIO_BUCKET_NAME' in os.environ
     bucket_name = os.getenv('MINIO_BUCKET_NAME')
     subfolder = 'models'
     # save image to buffer