fix licenses

This addresses two topics:

- The license/module key describes the license of the module (i.e. files
  in this repository) not that of the components contained in it.

- The license/components key should be left empty and filled in by the
  module build tools. This way, the respective current licenses of the
  components used for building are put in, and we don't have to maintain
  their licenses in two places.

ruby.yaml

@@ -11,15 +11,9 @@ data:
         object-oriented programming.  It has many features to process text
         files and to do system management tasks (as in Perl).  It is simple,
         straight-forward, and extensible.
-    # From *.spec License
     license:
         module:
-            - Ruby or BSD
-            - Public Domain
             - MIT
-            - CC0
-            - zlib
-            - UCD
     references:
         community: http://ruby-lang.org/
         documentation: https://www.ruby-lang.org/en/documentation/