Go Package with multiple subpackage

[Superfly Johnson]

The Azure SDK for Go 
(https://github.com/Azure/azure-sdk-for-go/releases) has many 
sub-packages within the same directory and the guix import method won't 
work directly. I think the best solution for packaging the requirements 
for rclone would be to make the sub-packages individual guix packages 
using the url-fetch method instead of the git method. Each also depends 
on several sub-packages.

Thoughts?