Remove popen function from test unit.
Remove popen function from test unit.

giuliolunati/fakechroot,solderzzc/fakechroot,andrewgregory/fakechroot,solderzzc/fakechroot,solderzzc/fakechroot,andrewgregory/fakechroot,andrewgregory/fakechroot,solderzzc/fakechroot,giuliolunati/fakechroot,solderzzc/fakechroot,giuliolunati/fakechroot