Include NRPyLeakage in next ET release

[Leonardo Werneck]

NRPyLeakage is a NRPy+-based code that provides neutrino leakage for GRMHD simulations. It computes the neutrino optical depths using a next-neighbors, path of least resistance algorithm that has been specially designed to work with the AMR grids provided by Carpet.

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

[Gabriele Bozzola]

Does this fix https://bitbucket.org/einsteintoolkit/tickets/issues/2497/illinoisgrmhd-is-incompatible-with-setting ?

[Roland Haas]

Terrence Pierre Jacques will review.