Update node version and dependencies.

Review Request #7862 — Created Jan. 12, 2016 and submitted — Latest diff uploaded

Information

student-sonar
master
d7b5811...

Reviewers

Sonar was running with a very old node engine, which had some vulnerabilities.
This change updates to the latest stable node release and also bumps our
backend package dependencies to the latest versions.

Flipped through the various pages and saw that everything worked as expected.