update regnet and detectron models (#951)
Summary:
- change regenet016 to regnet120
- update detectron2 to latest version
Pull Request resolved: https://github.com/pytorch/benchmark/pull/951
Reviewed By: xuzhao9
Differential Revision: D37026760
Pulled By: FindHao
fbshipit-source-id: ece8d4f3d5e6ed41b802ed0ab1d99c642c0f87f1
