Hi guix!

Here's a patch to add kanatest, a learning tool for japanese kana.

guix lint complains about
> URI https://git.code.sf.net/p/kanatest/code not reachable: 404 ("Not
> Found")

but cloning does work, so I don't know if I need to do something in
order to fix it.  I had to use git instead of the release tarball as
that is really old (2009), works only with gtk2 and I could not get it
to build.

Thanks!
Nicolò