Edit bower install script based on comments. Close gh-1392.

build/bower-install.js

@@ -1,5 +1,4 @@
-var installer,
-	which = require( "which" ),
+var which = require( "which" ),
 	spawn = require( "child_process" ).spawn;
 
 try {
@@ -8,16 +7,7 @@ try {
 	console.error( "Bower must be installed to build jQuery." );
 	console.error( "Please install Bower by running the following command:" );
 	console.error( "npm install -g bower" );
-	process.exit( 1 );
+	process.exit( 0 );
 }
 
-installer = spawn( "bower", [ "install" ] );
-installer.stdout.on( "data", function( data ) {
-	console.log( data );
-});
-installer.stderr.on( "data", function( data ) {
-	console.error( data );
-});
-installer.on( "close", function( code ) {
-	process.exit( code );
-});
+spawn( "bower", [ "install" ], { stdio: 'inherit' } );

package.json

@@ -42,7 +42,7 @@
 		"which": "~1.0.5"
 	},
 	"scripts": {
-		"install": "bower install",
+		"install": "node build/bower-install",
 		"test": "grunt"
 	}
 }