nightly-runtime-with-abi-one

Remove fmt from environment header (#78)

Summary:
Pull Request resolved: https://github.com/pytorch/multipy/pull/78

This makes it so we don't have to package fmt headers with oss deploy release.

Reviewed By: PaliC

Differential Revision: D37408294

fbshipit-source-id: bc11ae12f37b08239a054e087d286b3070686f3d