[object2vec] object2vec_multilabel_genre_classification.ipynb issues

https://github.com/awslabs/amazon-sagemaker-examples/blob/master/introduction_to_amazon_algorithms/object2vec_multilabel_genre_classification/object2vec_multilabel_genre_classification.ipynb

This notebook doesn't run end to end. It breaks with the following error:
`ParamValidationError: Parameter validation failed`

Start by opening and running object2vec_multilabel_genre_classification.ipynb from the linked example, recording the cell that raises ParamValidationError. Trace the failing parameter validation and rerun the notebook end to end; done means the complete notebook executes without that error.

Written by the indexing model from the issue text.