swift-package-manager

[PackageDescription] Make Package `name` required.

 - Prior to this change, the name would be inferred from the context (i.e. path
   or URL) from which the package containing the manifest was loaded. However,
   this is both cumbersome in the code and problematic bwith regard to case
   normalization as nothing guarantees that the file path or git URL path
   matches the author's intended casing.

 - In addition, the feature itself seems rarely used and less explicit, so I
   think moving to make this parameter is a natural choice.