Add omegaconf dependency to hubconf.py (fixes #3093) (#3102)
Add omegaconf dependency to hubconf.py (fixes #3093) (#3102)

Summary: Pull Request resolved: https://github.com/pytorch/fairseq/pull/3102

Reviewed By: alexeib

Differential Revision: D25784689

Pulled By: myleott

fbshipit-source-id: 66b0755e7f8abca2a522266bd58881b789bae581

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq