updated torch.load params

[bsh98]

Updated occurrences of torch.load to include map_location parameter. When attempting to train with --device set to cpu, torch.load may attempt to load a file with GPU tensors, which will lead to loading to GPU by default (see: https://pytorch.org/docs/stable/generated/torch.load.html). If --device is set to cpu, this will error on a cpu-only machine. Otherwise, it will go against desired functionality. This pull request resolves this issue.