Pre-download multi30k dataset for attention model (#937)
Summary:
Fixes broken link in https://github.com/pytorch/benchmark/blob/main/torchbenchmark/util/torchtext_legacy/translation.py#L82 by pre-downloading the data to data directory.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/937
Reviewed By: erichan1
Differential Revision: D36829304
Pulled By: xuzhao9
fbshipit-source-id: 330d66e47fafa4c9b20e0854b10a96a62cb75dce
