ignore files starting with . e.g. .ipynb_checkpoints (#819)
ignore files starting with . e.g. .ipynb_checkpoints (#819)

Summary:
.ipynb_checkpoints folder in models folders crashed the importlib
now there is a check for this
Pull Request resolved: https://github.com/fairinternal/fairseq-py/pull/819

Differential Revision: D16772192

Pulled By: myleott

fbshipit-source-id: 01c956aef4ed312bc7645c31c83dbf98af89d931

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq