title: Unable to find package . No packages exist with this id in source. .NET core
body: <p>I am trying to use a project as nuget package in other solution. 
  The project i want to use has 2 references to other projects in the solution he is at.
  I am creating the .nupkg file using the cli command <code>dotnet pack</code> in the path of the project i want to use as a nuget package.
  When adding the .nupkg file to the other solution using the command <code>dotnet add package</code> i get the error in the post title with the name of the 2 references projects.</p>