parquet_dataset.py Should it be isolated from deep learning framework？

[GitEasonXu]

https://github.com/intel-analytics/analytics-zoo/blob/1cb1ee16fd5f0c04ac0e17542ec2a8fa0b65217d/pyzoo/zoo/orca/data/image/parquet_dataset.py#L34

When I use the ParquetDataset, I will get ModuleNotFoundError: No module named 'torch', if I‘m a tensorflow user.

[yangw1234]

@GitEasonXu this has been fixed on latest master.

[helenlly]

@GitEasonXu any more questions on the issue? if no, we will close the issue.