tools: use local or specified $NODE for test-npm
See: https://github.com/nodejs/io.js/pull/1955#discussion_r32291327
cc @nodejs/build
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
See: https://github.com/nodejs/io.js/pull/1955#discussion_r32291327
cc @nodejs/build