Fixes def test_exceptions_inherit_from_Exception -
  def test_raising_a_particular_error. I learned:

* .ancestors[x] calls the ancestor x spots back from the object.

* 'raise' and 'fail' are synonyms
     
[#65851862]
Fixes last two errors in about_exceptions.rb

[#65851862]
Merge pull request #14 from kkburr/65851862_about_exceptions_master

about exceptions master

[Delivers #65851862]