Add node 6.16.0, remove node 6.15.1
Add node 6.16.0, remove node 6.15.1

for stack(s) cflinuxfs2, cflinuxfs3 [#162848357]

cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack,cloudfoundry/ruby-buildpack