Upgrade to glTF 1.0 Format

[tparisi]

@HeavyD @lokeuei hey guys, got this repo going. Dave, Loke is going to help us get the glTF Unity exporter going again. You're both collaborators on this repo.

First up, let's upgrade to 1.0 format (from whatever version this supported a year ago!)

[christimahu]

What's needed for this?