make test fails on OSX

On OSX 10.10, make test fails:

$ make test
ruby tools/test.rb
This will take a few minutes...
sh: fakechroot: command not found
URANDOM Exit Status FAILED!

Related to #22.

All other tests pass, it's just the two that require fakechroot that break it.

@defuse How do you feel about adding a check to see if "fakechroot: command not found" is found in the output, and if so, skip those two tests? That would make fakechroot optional (though could be recommended), which would solve this issue.

This will also be an issue for #20, but that's a discussion for another ticket.