Mark PyTorch incompatible with python-3.6.0 (#34724)
Summary:
Per https://github.com/pytorch/pytorch/issues/19161 PyTorch is incompatible with 3.6.0 due to the missing `PySlice_Unpack`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34724
Test Plan: CI + try to load pytorch binary using python-3.6.0
Differential Revision: D20449052
Pulled By: malfet
fbshipit-source-id: 2c787fc64f5d1377c7f935ad2f3c77f46723d7dd
