Got all tests on about_objects.rb to pass

* Everything in Ruby is an object and has a unique id, even if the object is cloned.

* Objects can be converted to strings using .to_s method.

* Small integers have fixed object ids: 
(0..10).each { | i | print i.object_id, ' ' }
1 3 5 7 9 11 13 15 17 19 21 

[#54146139]