We need a mechanism to support authenticated feeds with package management.

nuget has an authenticated feeds mechanism where credentials are required to access a feed.

We need a mechanism to allow notebook users access to these types of feeds, however ... putting plaintext credentials in script files, or indeed any other type is not really very secure, so we should come up with something a little more secure than that. Ideally without us doing any credential management or storage in our code, because the security is so hard to get right.