Having a non-empty dir at this URL: data://asli/xgboost_iris_demo:

• First trying algo rmdir xgboost_iris_demo and I get no response, so as a user I'm not sure if the CLI deleted this dir or not. - So I go and check and see that it's still there. For this case, I would expect to get a message like "dir not found, you should specify it like this etc"
• Then I re-try with algo rmdir asli/xgboost_iris_demo and the CLI warns me. About this step, do we want to expose all our error trace to the end user? Shouldn't we just return a message to the user?