Fix to support private modules.

- No longer exists early when it checks a package it can’t find in npm.
- Prints nice message if it can't upgrade a package.

I realize there's another pull request for a similar fix, but I already finished this so I figured maybe the author can see them both so he/she has not only two ways to fix it but could choose to use the PR's to write their own way!

I just want to see this feature get added into NPM.