Add option to disable positional embeddings in TransformerModel (#421)
Add option to disable positional embeddings in TransformerModel (#421)

Summary:
Add argument `--no-token-positional-embeddings` to TransformerModel (currently only available in TransformerLanguageModel) to disable positional embeddings.
Pull Request resolved: https://github.com/pytorch/fairseq/pull/421

Differential Revision: D13548450

Pulled By: myleott

fbshipit-source-id: b352c702ed1609e3b84d9a8404941d3274a7f883

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq