Enable Fastly on GitLab.com as CDN

Start by enabling in Canary to test, then enable in production.

Configure canary to use Fastly as a CDN and prove out URL usage and loading speeds as a pre-check for a trial run on GitLab.com

In https://gitlab.com/gitlab-com/infrastructure/issues/2092 we evaluated CDN providers with pros and cons and elected a winner to move forward with testing of.

Edited Sep 20, 2017 by John Northrup