appeasing flake8, also cleaning up header
appeasing flake8, also cleaning up header

The header append lines were too long, so I just converted it into a
multi-line string template so it's all one piece now instead of a bunch
of appends.

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