Mattermost is an open source, self-hosted alternative to the Slack SAAS messaging service. In other words, with Mattermost, you can setup a private and dedicated messaging server on your own machine for your team. - A newly created Vultr CentOS 7 x64 server instance. Say its IP address is `203.0.113.1`. - A [sudo user](https://docs.vultr.com/how-to-use-sudo-on-a-vultr-cloud-server). - The server instance has been [updated to the latest stable status using the EPEL YUM repo](https://docs.vultr.co......