Bug Description

If the project includes punycode as a dependency in package.json, it gets listed as unused even when it's not.

This is because punycode is also included as a builtin in the Node API, but as it's been deprecated there since v0.7 it should now be included as an explicit dependency.

In fact, given that's it deprecated in the NodeJS API and has been for a long time, it might be helpful to list it as a missing dependency if it's used but hasn't been explicitly declared as a dependency in package.json.

See https://nodejs.org/api/punycode.html#punycode_punycode