Investigate GPU processing for PathSearch

[e-lo]

GPUs specialize in massively parallel computations, but are memory constrained.

There is a python library to use: https://mathema.tician.de/software/pycuda/

Some papers on using CUDA for graph searches:

http://cvit.iiit.ac.in/papers/Pawan07accelerating.pdf

Due to the restriction of memory on the CUDA device,
graphs above 12 million vertices with 6 degree per vertex cannot be handled using
current GPUs.

Obviously the degree here doesn't work in our favor...but it is probably a balance between that and vertices.

https://arxiv.org/abs/1002.4482