test/file_cache.py: ported to pytest (#3429)
test/file_cache.py: ported to pytest (#3429)


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