Fixed about_scope.rb to pass tests

Learned that:
* you can reference nested classes using the scope operator,
* nested string is not the same as the system string,
* we can use the prefix scope operator to force the global scope.

[#65851792]
Fixed about_scope.rb to pass tests

Learned that:
* constants are defined with an initial uppercase letter,
* class names are just constants,
* constants can be looked up explicitly,
* you can get a list of constants for any class or module.

[#65851792]
Merge pull request #24 from mkreyman/65851792_about_scope_master

about scope master

[Delivers #65851792]