Support for latest node 4.x / 5.x

[springmeyer]

Low priority but will block eventually. The directory structure of latest node v4/5 for the headers is different. We'll need to adapt this to in order to avoid errors like:

gyp ERR! stack Error: node-v4.4.1-headers.tar.gz local checksum e759ee28a27dc47a5c80e48b063c0bee015f3b6d2f8f593ad0eabfab0ebb3922 not match remote undefined

/cc @BergWerkGIS

[springmeyer]

The upcoming node-mapnik release: v3.6.1 will work fine with the stock nodejs binaries. So this repo has been deprecated: https://github.com/mapbox/node-cpp11/blob/master/README.md#deprecated