Update about_strings.rb

Update single character representation test for Ruby 2.
Trimmed artistic end message to 79 columns.

On Windows, the standard terminal will insert a blank line after
any 80-column line.  Yes, this is a silly way for a terminal to
work, but on Windows, this is likely to happen.  Trimming to 79
columns makes things much less ugly.
Initial minor changes (grammatical in methods; require -> require_relative in tri...).
Fixed another small grammatical mistake (. to ? in dice file)
Made a minor readability change to a comment in about_blocks.rb
Merge pull request #104 from michael-gebis/master

Cosmetic change for the benefit of Windows users.
Internalized assertions.

This makes us independent of test/unit and minitest.
Shorter stack traces, even on exceptions.
Update zip file.
Merge pull request #111 from smlance/changes-1

Minor changes to existing koan files
Merge branch 'master' of https://github.com/mhenry07/ruby_koans into mhenry07

* 'master' of https://github.com/mhenry07/ruby_koans:
  Update about_strings.rb
Using the term 'modern ruby'
Update zip file.