update uglify-js from 2.4.23 to 2.6.0
update uglify-js from 2.4.23 to 2.6.0

Two security vulnerabilities:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8857
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8858
EditLLC/javascript-montage,EditLLC/javascript-montage