install aurelia-http-fetch steps

instructions.txt

steps to install fetch

npm install whatwg-fetch --save 
npm install aurelia-fetch-client --save

in aurelia.json, add thse to the vendor-bundle.js
"aurelia-fetch-client",
{
 "name": "whatwg-fetch",
 "path": "../node_modules/whatwg-fetch",
 "main": "fetch"
},

in main.ts, add this line
import 'whatwg-fetch';

and install typings libraries
typings install dt~whatwg-fetch --global --save
typings install dt~whatwg-streams --global --save
typings install github:RomkeVdMeulen/URLSearchParams --global --save