www/node8: Update 8.10.0 -> 8.11.0

This is a security release addressing multiple vulnerabilities. Users
are recommended to upgrade as soon as possible.

https://nodejs.org/en/blog/vulnerability/march-2018-security-releases/
https://nodejs.org/en/blog/release/v8.11.0/

MFH: 2018Q1
Security: 5a9bbb6e-32d3-11e8-a769-6daaba161086