Natively Render sketch files

Issue idea came from: https://gitlab.slack.com/archives/C0GQHHPGW/p1490627651057802

Description

Currently we show a preview of the Sketch file according to the last edited page (example).

This would be awesome for both developers as well as designers in order to inspect the files, without needing to open it in Sketch or a different application. Example: https://github.com/AnimaApp/sketch-web-viewer

Proposal

Be able to inspect this file in gitlab. This now becomes a viable option as sketch changes their file format as of v43 also see:

• http://sketchplugins.com/d/87-new-file-format-in-sketch-43

Value

If we are fast to act on this, we can grab a lot of designer attention with this!