gollum: 4.1.3 -> 4.1.4 (security, CVE-2018-3740)
(cherry picked from commit 18b468ed8186131d5a8a6590ff10253e12d0195a)
Reason: Security update: "Depend on new version of gollum-lib that
relies on a patched version of sanitize, which solves a vulnerability
(CVE-2018-3740). See https://github.com/gollum/gollum-lib/pull/296."