Enforce kw-only args now that py2 is unsupported (#37069)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/37069
Test Plan: Imported from OSS
Differential Revision: D21204729
Pulled By: nairbv
fbshipit-source-id: 8e93decae59e753706fa288bcdc3bf6278b8eeb5
