update torus.py to use absolute paths

[DininduSenanayake]

Running inference on a Slurm cluster with sbatch failed to create the cache file .score.npy on the expected path as torus.py was using relative paths which doesn't get inherited correctly during the submission. Plus torus.py failed to trigger a meaningful message as to why the cache file wasn't on the expected path. This modified version

1. will look for and save the cache files in the same directory as the script itself, regardless of where the script is being run from
2. added debugging prints will help you see if/when the cache files are being created
3. script will explicitly check that both required cache files exist before trying to load them