Workaround for failed build caused by https://nodejs.org redirect

Builds of #160 and #159 failed due to https://github.com/eirslett/frontend-maven-plugin/issues/99 which originated from nodejs.org chainging their policy and now serving contentn through https:// only.

This is workaround to get build green on Travis again, clean build will require to have node.js installed on a machine

rontend-maven-plugin version should be bumped later after to have a proper fix.