Add Bob Robey to README credits.
Add Bob Robey to README credits.

EmreAtes/spack,lgarren/spack,EmreAtes/spack,iulian787/spack,mfherbst/spack,krafczyk/spack,iulian787/spack,matthiasdiener/spack,skosukhin/spack,mfherbst/spack,mfherbst/spack,skosukhin/spack,TheTimmy/spack,tmerrick1/spack,TheTimmy/spack,tmerrick1/spack,krafczyk/spack,iulian787/spack,LLNL/spack,matthiasdiener/spack,LLNL/spack,mfherbst/spack,EmreAtes/spack,lgarren/spack,tmerrick1/spack,skosukhin/spack,matthiasdiener/spack,TheTimmy/spack,mfherbst/spack,TheTimmy/spack,krafczyk/spack,EmreAtes/spack,tmerrick1/spack,matthiasdiener/spack,skosukhin/spack,LLNL/spack,LLNL/spack,krafczyk/spack,skosukhin/spack,lgarren/spack,lgarren/spack,matthiasdiener/spack,iulian787/spack,tmerrick1/spack,iulian787/spack,krafczyk/spack,TheTimmy/spack,EmreAtes/spack,lgarren/spack,LLNL/spack