stepping down as maintainer

[Jordi Burguet Castell]

Hi Brian,

> Hello. It's time for me to step down as maintainer of GSL.  If anyone
> wants to take over the role please contact maintainers@gnu.org.

I just wanted to thank you so much! All your effort and hard work has
shown and as a result the GSL is an excellent library, that I among
many others have greatly enjoyed using.

All the best,
Jordi