Install a newer version of Node by default

Created by: brock

The script currently installs 0.10, but that is getting pretty outdated. #30 (closed) will take care of matching a version that is already installed, but for new installations I'm considering just bumping this to 5.0.

Open to thoughts if anyone has them.

NVM supports running nvm install node which is like nvm install stable. I'm open to that, but I'll have to see if Nave supports the same.