How do I add a .NET Core 1.1 Class Library dll to ASP.Net core 1.1 project

Both project are on .NET core 1.1.

The dll is added to the project in Dependencies -> Assemblies. When I publish the asp.net core web site, I can see the dll in the root folder. The web application runs fine until my code calls the dll, which gives me:

FileNotFoundException: Could not load file or assembly 'Test.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.

Is there a config/json file that I need to update the reference?

How can I make this work?

Thanks,
Patrick