Extension doesn't work with 3.16

Created by: tstriker

this is a preemptive report as i won't be running 3.16 myself until fedora's beta comes out.

If somebody's actually already running 3.16, please check if it works straight out of the box: simply add "3.16" here https://github.com/projecthamster/shell-extension/blob/master/metadata.json#L14 and report back!