I'm also getting the same error: any updates on this one ?
centos 6.6 64
postgres 8.4
udo -u mattermost ./platform
[2017/03/18 07:16:30 PDT] [INFO] Loaded system translations for 'en' from '/opt/mattermost/i18n/en.json'
[2017/03/18 07:16:30 PDT] [INFO] Current version is 3.7.0 (3.7.2/Fri Mar 17 19:07:10 UTC 2017/f4473cf312d09a53a57312745963aee334e251cb/c737afff891a25ee3b011c0d4b1392adc3dcc622)
[2017/03/18 07:16:30 PDT] [INFO] Enterprise Enabled: true
[2017/03/18 07:16:30 PDT] [INFO] Current working directory is /opt/mattermost/bin
[2017/03/18 07:16:30 PDT] [INFO] Loaded config file from /opt/mattermost/config/config.json
[2017/03/18 07:16:30 PDT] [INFO] Server is initializing...
[2017/03/18 07:16:30 PDT] [INFO] Pinging SQL master database
[2017/03/18 07:16:30 PDT] [CRIT] Error creating database tables: pq: syntax error at or near "not"