Modification to grmEstimatorToolbox

The grmSimulation.py file has been modified by Bradley Setzler to include two additional features: (1) calculate and export conventional treatment effects from the simulated data and (2) make data and treatment effect simulation parallel via MPI. 

To accomplish (2), I separate the master simulation function, simulate(), from the worker simulation to be completed on parallel processes, workerSimulate(). To accomplish (1), I add the treatment computations to workerSimulate(). 

All additions to the Generalized Roy Toolbox are fully contained in grmSimulation; no other components of the Generalized Roy Toolbox need be modified to achieve (1) and (2).