Update PyTorch version #3
Description
#1 uses PyTorch 0.4.1, but there really isn't any reason not to use PyTorch 1.0... except the fact that NVVL's "old" PyTorch module (https://github.com/jsjason/nvvl/tree/master/pytorch) is incompatible with PyTorch 1.0. After #1 is merged, we should update both NVVL and PyTorch to the latest versions.