Loading Vega-lite schema + data from local

[sohenrane]

Apparently, even loopback webservice does not load the files.

{
"$schema": "http://127.0.0.1:8000/v5.json",
"title": "Seattle Weather, 2012-2015",
"data": {
"url": "http://127.0.0.1:8000/seattle-weather.csv"
}
}