Ack: add version 2.18 (#5445)
Ack: add version 2.18 (#5445)


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