I applied all your suggestions :)

> If you’re confident with the licenses and ‘guix lint’ is happy,
> please push!

Almost all of Julia packages are under MIT (expat), I double checked and
they are fine.  Also, 3 packages (out of 8) have been updated since my
submission, so I updated them now and guix lint does not complain anymore.

> Nice to see more Julia packages.

This is the first batch, I finally decided to submit in small batches
the 100+ packages I have; you have been warned :D

Here's the updated patchset (if somebody can push).

Thanks Ludo for the review