Revert https://github.com/mapbox/mason/commit/fab963a25627067c520ebfd871ae799ec315408f #515
Description
fab963a leads to
* Done linking /home/travis/build/mapnik/node-mapnik/mason_packages/linux-x86_64/boost_libsystem/1.63.0
basename: missing operand
Try 'basename --help' for more information.
* Downloading binary package https://mason-binaries.s3.amazonaws.com/linux-x86_64/boost_libfilesystem/1.63.0.tar.gz
on OS X. /cc @tpikonen @artemp (who plans to test #492 tomorrow)