Spike / PoC for Mac Shared Runners

Goal

This issue is for capturing work done to learn what we need to do to build out a macOS shared runners offering for GitLab.com on top of our autoscaler.

There's deliverable in the normal sense, I don't expect us to create an MR related to this that gets merged to the main code base. Instead the outcomes should be, but not necessarily limited to:

• Gaining familiarity with API’s, SDKs, terminology, etc needed to build such an offering
• Creating a “full” set of issues laying out the work remaining to build out a macOS shared runner platform

Documentation

• Developer Getting started
• Portal
• API Documentation

Dev log

2020-02-24

• Go through quickstart and workflows
• Simple PoC to provision VMS

202-02-25

• Finish PoC