What is the state and roadmap for this API 
Dear Sketch,

Greg Kerzhner here from InVision.  We are currently exploring using this API for our Craft plugins instead of relying on your private headers which change often.  However, by briefly browsing this repo, its not clear what state this API is in.  The docs say "its still very much a work in progress".  Is it in alpha, beta, or are parts of it ready to be used in production.  Is there a road map and timeline for getting this API production already? Are others already using it in production?  

Thanks!
Greg