Do not vendor cookbooks using Berkshelf anymore

Instead, use the Berkshelf support in knife-solo and the
vagrant-berkshelf plugin on Vagrant

cookbooks/nodejs/recipes/npm_packages.rb

@@ -1,11 +0,0 @@
-node['nodejs']['npm_packages'].each do |pkg|
-  pkg_action = pkg.key?('action') ? pkg['action'] : :install
-  f = npm_package "nodejs_npm-#{pkg['name']}-#{pkg_action}" do
-    action :nothing
-    package pkg['name']
-  end
-  pkg.each do |key, value|
-    f.send(key, value) unless key == 'name' || key == 'action'
-  end
-  f.action(pkg_action)
-end if node['nodejs'].key?('npm_packages')