Updating LBANN and related packages (#10305)

Updated LBANN, Hydrogen, and Aluminum to not require CUDA-aware MPI
even when using CUDA.  Fixed small bugs within both LBANN and Hydrogen
packages.  Added requirements for breathe and cereal to LBANN.

var/spack/repos/builtin/packages/aluminum/package.py

@@ -29,8 +29,7 @@ class Aluminum(CMakePackage):
     depends_on('cuda', when='+gpu')
     depends_on('cudnn', when='+gpu')
     depends_on('cub', when='+gpu')
-    depends_on('mpi', when='~mpi_cuda')
-    depends_on('mpi +cuda', when='+mpi_cuda')
+    depends_on('mpi')
     depends_on('nccl', when='+nccl')
     depends_on('hwloc')