knowledge.war creation is broken

[paddy-hack]

Trying to build the knowledge.war file for a minor customization, I ran into several problems. The most important ones are that

• mvn clean package does not include files that match one of WEB-INF/views/**/*.jsp,bower/**/*
• the latest fs-extra has dropped support for Node.js 6

when I try to build in a mvn:3.5-jdk-8-slim Docker container (as per Dockerfile).

I'm working on a PR to fix this.