Quant Noise
Quant Noise

Summary: Implemented fix bit scalar quantization with quant noise for pytext models

Reviewed By: AkshatSh

Differential Revision: D29662977

fbshipit-source-id: ebab68a4a5ff1583a0c6dfadcf2671663e232c18

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq