Vega-Lite specification created by @churtado.
forked from domoritz's block: Vega-Lite block example
https://cdnjs.cloudflare.com/ajax/libs/vega/3.0.0-beta.38/vega.js
https://cdnjs.cloudflare.com/ajax/libs/vega-lite/2.0.0-beta.5/vega-lite.js
https://cdnjs.cloudflare.com/ajax/libs/vega-embed/3.0.0-beta.19/vega-embed.js