After following this, I still get the following error:
$> sudo -u mattermost /opt/gitlab/embedded/bin/mattermost -config="/var/opt/gitlab/mattermost/config.json" -create_team -team_name="testteam" -email="me@example.com"
[09:11:07 BST 2016/03/29] [INFO] (github.com/mattermost/platform/utils.GetTranslationsBySystemLocale:52) Loaded system translations for 'en' from '/opt/gitlab/embedded/service/mattermost/i18n/en.json'
[2016/03/29 09:11:07 BST] [EROR] createTeam: ,Installation is Gitlab/Mattermost omnibus on CentOS 7 where the Mattermost version reports as follows:
$> sudo -u mattermost /opt/gitlab/embedded/bin/mattermost -config="/var/opt/gitlab/mattermost/config.json" -version
[09:12:59 BST 2016/03/29] [INFO] (github.com/mattermost/platform/utils.GetTranslationsBySystemLocale:52) Loaded system translations for 'en' from '/opt/gitlab/embedded/service/mattermost/i18n/en.json'
Version: 2.1.0
Build Number: 2.1.0
Build Date: Mon Mar 14 20:45:23 UTC 2016
Build Hash: f189bc2073cf800c5f4506a69bdb51d7065269bf
Build Enterprise Ready: false