.circleci: Remove manual docker installation (#43277)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43277
Docker added native support for GPUs with the release of 19.03 and
CircleCI's infrastructure is all on Docker 19.03 as of now.
This also removes all references to `nvidia-docker` in the `.circleci` fodler.
Signed-off-by: Eli Uriegas <eliuriegas@fb.com>
Test Plan: Imported from OSS
Reviewed By: ezyang
Differential Revision: D23217570
Pulled By: seemethere
fbshipit-source-id: af297c7e82bf264252f8ead10d1a154354b24689
