optional new transport layer: pycall

[rvalyi]

see https://github.com/mrkn/pycall.rb https://www.practicalai.io/using-scikit-learn-machine-learning-library-in-ruby-using-pycall

as an option: try a layer requiring a valid python path to look with see if it is faster than JSON/RPC if it is faster it could be use in some cases.