Git commits in Moodle 2.7.18 by Vladimir Zhirov

commit 41203623958643a76358f920a184ecf03a65b2dd
Author: Vladimir Zhirov <vvzh@users.noreply.github.com>
Date:   Sun, 27 Nov 2016 03:42:54 +0800
Tag:    v2.7.18

MDL-57163 installation: fixed "Call to undefined function curl_version"