added zlib dependency to glib package specification
added zlib dependency to glib package specification

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