use native nodejs installation

Index: node-window-size/cli.js
===================================================================
--- node-window-size.orig/cli.js
+++ node-window-size/cli.js
@@ -1,4 +1,4 @@
-#!/usr/bin/env node
+#!/usr/bin/env nodejs
 'use strict';
 var helpText = ['Usage',
 '  $ window-size',