fix(core): switch from typings-global to @types/node

ts/index.ts

@@ -1,6 +1,9 @@
-import 'typings-global'
-import open = require('open')
+import open = require('opn');
+import { ChildProcess } from 'child_process';
 
-export let openUrl = async (urlArg) => {
-  open(urlArg)
-}
+export let openUrl = async urlArg => {
+  const childProcess = await open(urlArg, {
+    wait: false
+  });
+  return childProcess;
+};