message: Remove redundant MPI_C_COMPILER and MPI_CXX_COMPILER
diff: # MPI - manually added for now
  ##############################################################################
  set(ENABLE_MPI ON CACHE PATH "")
  -#set(MPI_C_COMPILER "/usr/apps/gnu/clang/llnl/bin/mpiclang-fastmpi" CACHE PATH "")
  -#set(MPI_CXX_COMPILER "/usr/apps/gnu/clang/llnl/bin/mpiclang++11-fastmpi" CACHE PATH "")
  set(MPI_C_COMPILER "/usr/apps/gnu/clang/r266321-20160414/mpi/bgclang-mpi3/bin/mpicc" CACHE PATH "")
  set(MPI_CXX_COMPILER "/usr/apps/gnu/clang/r266321-20160414/mpi/bgclang-mpi3/bin/mpicxx" CACHE PATH "")
  