I left a TODO note about the way our MPI command construction doesn't preserve JSON encoding rather than fixing it to keep this PR small and narrowly-focused, but will hopefully fix it in a future PR.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
Description of changes: Corresponds to https://github.com/aws/sagemaker-pytorch-container/pull/87 and https://github.com/aws/sagemaker-pytorch-container/pull/88 (but for Chainer)
I left a TODO note about the way our MPI command construction doesn't preserve JSON encoding rather than fixing it to keep this PR small and narrowly-focused, but will hopefully fix it in a future PR.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.