Upgrade to newer node version for improved build speeds
The v8 engine is showing very substantial performance improvements in recent versions and keeping on top of recent node versions will have a positive impact on build performance for our frontend assets.
This is especially true for certain tools which are build taking recent version's optimizations into account. Webpack's maintainer, for instance, suggests running builds on node >= v8.9.4 for optimal build performance in the latest version.
https://twitter.com/wSokra/status/967852475918274561
/cc @twk3