Re: [PATCH] gnu: Add nim.

[David Craven]

Hi Jose,

Some changes I made:

* change module name to (gnu packages nim).
* reorder imports alphabetically.
* added you to the copyright header.
* added a comment as to why the tests are disabled.
* returned true after substitute*
* used (zero? (system* "./install.sh" ...
* removed new line after description
* added a trailing dot to the commit message headline

I don't think we need a separate /opt subfolder, opt is basically
/gnu/store for FHS systems.

Pushed as 84aafbbb664925ed1a9de3e53238bc54c743a968. Thank you!