Update maintainer. Refs #245.

Jonathan Laurent is listed as maintainer of copilot-theorem even though
he has not worked with us in several years.

This change updates the maintainer for that package to be the same as
the one of all other packages at the moment.

Author: ivanperez-keera

lib/copilot-theorem/copilot-theorem.cabal

@@ -17,7 +17,7 @@ description:
 version                   : 3.4
 license                   : BSD3
 license-file              : LICENSE
-maintainer                : jonathan.laurent@ens.fr
+maintainer                : Ivan Perez <ivan.perezdominguez@nasa.gov>
 homepage                  : https://copilot-language.github.io
 bug-reports               : https://github.com/Copilot-Language/copilot/issues
 stability                 : Experimental