Update dist-url for build.js script

[vldmitrofanov]

trafficstars

DIST URL https://atom.io/download/electron is no longer working

Expected Behavior

npm run build:ci should work

Current Behavior

npm run build:ci fails because cannot download headers

Possible Solution

replace args.push('--dist-url=https://atom.io/download/electron'); in build.js change --> args.push('--dist-url=https://artifacts.electronjs.org/headers/dist');

Steps to Reproduce (for bugs)

npm run build:ci