git tag with scoped package notation issue `@`

[ramasilveyra]

npm 5 and yarn can't that can handle git tags with @scope/name-package-1.0.0-gitpkg notation (last time tested).

That it's why I temporarily changed to a normalised version of scoped packages in #1

[cjancsar]

How do you upgrade a scoped dependency? Once pushed with gitpkg I can't upgrade the package downstream with yarn...

yarn upgrade @my-scope/my-pkg@tag spits errors