Update NodeJS 6 to latest 6.11.x LTS

[csantanapr]

Update to latest NodeJS and review pre-installed packages versions

[csantanapr]

We will skip 6.10.1 and go for 6.10.2
Re: nodejs/node#12037

[csantanapr]

Will go for 6.11.4 new runtime image being updated here https://github.com/apache/incubator-openwhisk-runtime-nodejs