Re: 403 on npm install

Hi,

appdynamics version 4.2.1 has the following limitation in its package.json:
`engines: { node: '>=0.8.0 <=5.7.1' }`

So anybody using the latest version of node can't use appdynamics.
It would be nice from AppDynamics to avoid setting an maximum version for Node, specially since it keeps moving forward.

Having a list a tested and supported version should be enough.