Updating installers, scripts and images with new Mattermost download name and location

If you've made an installer, script or image with Mattermost, we'd like to ask your help to update it to the new download file name and location:

1. As of Mattermost 2.1, downloading Mattermost will move to the following location and format: wget https://releases.mattermost.com/2.1.0/mattermost-team-2.1.0-linux-amd64.tar.gz instead of the previous location on GitHub. The GitHub archive will be removed. Links to archives of previous releases are available in the upgrade guide.

2. Also, if you're linking to the Mattermost changelog in your documentation, please note that the is not moved to the docs repository. This makes it easier to make updates during the monthly lock-down period for mattermost/platform just before release.