gopkg.in/srwiley/oksvg.gradfix does not resolve

[probonopd]

I would like to import the gradfix branch of https://github.com/srwiley/oksvg.

gopkg.in/srwiley/oksvg.gradfix does not resolve to the gradfix branch of https://github.com/srwiley/oksvg, instead it says

Unsupported URL pattern; see the documentation at gopkg.in for details.

Why?

Reference: https://github.com/srwiley/oksvg/issues/15#issuecomment-576441957