io.directories.search: fix traversal test case cross-platform issues.
io.directories.search: fix traversal test case cross-platform issues.

on Linux and macOS mojave they entries might traverse (a,c,b)
instead of (a,b.c) so we preserve the traversal method order
but sort for cross-platform testing.

tgunr/factor,factor/factor,bpollack/factor,mrjbq7/factor,bpollack/factor,bpollack/factor,tgunr/factor,AlexIljin/factor,factor/factor,mrjbq7/factor,mrjbq7/factor,bpollack/factor,tgunr/factor,tgunr/factor,factor/factor,AlexIljin/factor,bpollack/factor,factor/factor,mrjbq7/factor,mrjbq7/factor,AlexIljin/factor,AlexIljin/factor,factor/factor,AlexIljin/factor,AlexIljin/factor,bpollack/factor,bpollack/factor,tgunr/factor,AlexIljin/factor,tgunr/factor,mrjbq7/factor,factor/factor