Add node 6.9.1, remove node 6.8.1
Add node 6.9.1, remove node 6.8.1

source url: https://nodejs.org/dist/v6.9.1/node-v6.9.1.tar.gz, source sha256: a98997ca3a4d10751f0ebe97839b2308a31ae884b4203cda0c99cf36bc7fe3bf

[#132796533]

pkumar-appd/nodejs-buildpack,roder/nodejs-buildpack,cloudfoundry/nodejs-buildpack,ks2software/nodejs-buildpack,ks2software/nodejs-buildpack,ks2software/nodejs-buildpack,ks2software/nodejs-buildpack,kauffecup/nodejs-buildpack,pkumar-appd/nodejs-buildpack,ks2software/nodejs-buildpack,oocl-ncc-itm/nodejs-buildpack,roder/nodejs-buildpack,kauffecup/nodejs-buildpack,ks2software/nodejs-buildpack,cloudfoundry/nodejs-buildpack,pkumar-appd/nodejs-buildpack,cloudfoundry/nodejs-buildpack,oocl-ncc-itm/nodejs-buildpack,ks2software/nodejs-buildpack,roder/nodejs-buildpack,oocl-ncc-itm/nodejs-buildpack,kauffecup/nodejs-buildpack,cloudfoundry/nodejs-buildpack