Add Guix package recipe.
Add Guix package recipe.

This includes definitions for packages that are not in Guix upstream,
such as the Meme suite and the latest Bedtools from git (as the latest
release version segfaults).

* package.scm: New file.

dyusuf/RCAS,dyusuf/RCAS,BIMSBbioinfo/RCAS-tools,BIMSBbioinfo/RCAS-tools,BIMSBbioinfo/RCAS-tools,dyusuf/RCAS