Git commits in Moodle 3.1.8 by David Mudrák

commit 26663756fbf9efed48d70ddc61992edeb4567fd9
Author: David Mudrák <david@moodle.com>
Date:   Wed, 30 Aug 2017 01:01:40 +0800
Tag:    v3.1.8

MDL-59969 admin: Warn admins if a development libs directory exists