basset_motifs_predict.lua does not work with GPU-trained model

[jmrinaldi]

basset_motifs_predict.lua expects a CPU-trained model, making basset_motifs.py non-functional for GPU-trained models.

Converting all model tensors to double solves problem, may want to add this functionality

[davek44]

Ah great. In general, moving models back and forth between the GPU and CPU can be tricky, so I don't want to make a ton of promises there. I added support for a GPU model to that script though.