Add node 6.9.0, remove node 6.8.0
Add node 6.9.0, remove node 6.8.0

source url: https://nodejs.org/dist/v6.9.0/node-v6.9.0.tar.gz, source sha256: 2e2657d2ece89782ca9e2cc0300f9119998e73382caa7ad2995ab81cc26ad923

[#132691907]

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