update package.json. This is relase v4.0.0
update package.json. This is relase v4.0.0

kyroskoh/tilelive,tomhughes/tilelive.js,gravitystorm/tilelive.js,mapbox/tilelive,paulovieira/tilelive,mapbox/tilelive.js,topwood/tilelive,Norkart/tilelive.js,nyurik/tilelive.js