Fixed about_constants.rb to pass tests

Learned about:
* nested and top level constants,
* and how they are referenced.

[#65851762]
Fixed about_constants.rb to pass tests

Learned about:
* constants being inherited from enclosing classes,
* and from parent classes;
* and that nested constant wins over inherited,
* unless the scope is explicitly defined.

[#65851762]
Merge pull request #11 from mkreyman/65851762_about_constants_master

about constants master

[Delivers #65851762]