Upgrade: add 4.0 upgrade guide (#250)

- also upgrade dependencies

Fixes jquery/jquery#5365

Author: timmywil

Gruntfile.js

@@ -1,5 +1,3 @@
-var async = require( "async" );
-
 module.exports = function( grunt ) {
 
 grunt.loadNpmTasks( "grunt-jquery-content" );

config-sample.json

@@ -1,5 +1,5 @@
 {
-	"url": "vagrant.jquery.com",
-	"username": "admin",
-	"password": "secret"
+	"url": "http://local.jquery.com",
+	"username": "dev",
+	"password": "dev"
 }