Include NRPyEOS in next ET release

[Leonardo Werneck]

NRPyEOS is a NRPy+-based code to handle finite temperature, microphysical equation of state tables. It provides efficient interpolation routines and a clear user interface. The NRPy+ code that generates the thorn can be easily modified to generate wrapper functions that interpolate any combination of table quantities.

To access the NRPyEOS code, see: https://github.com/IllinoisGRMHD