fix bugs and bump version

[pfliu-nlp]

This PR should be able to fix:

• https://github.com/neulab/explainaboard_client/issues/25
• https://github.com/neulab/explainaboard_client/issues/26
• https://github.com/neulab/explainaboard_client/issues/27

Clearly, we need to do some integration tests for this repo.