GitLab

* [fix] optim/oss: support optimizers with additional step kwargs

Some of the optimizers in apex support additional kwargs to step
such as scale.

* move the restored param groups to the original device

* adding a corresponding test

* hotfix a half-cooked optimizer state restoration, the global shared state also needs to be restored

* [cleanup] get 100% coverage on oss.py (#38)
authored-by: Mandeep Singh Baines <msb@fb.com>

* better unit testing, check that the .param_groups attribute is properly in sync with the loaded state
Co-authored-by: msbaines <35972327+msbaines@users.noreply.github.com>

Aligning OSS state dict with `https://pytorch.org/docs/stable/_modules/torch/optim/optimizer.html#Optimizer` (#31)

Co-authored-by: Min Xu <m1n@fb.com>