ruby 1.8.7 fixes

catch simplecov when it blows up on 1.8.7, it's not that important anyway
only include pry in non 1.8.7
remove require relative stuff, as it doesn't work in 1.8.7
ruby 1.8.7 string slice fix

Ruby 1.8.7 'helpfully' returns the character code instead of the character when
you reference an index in an array. This commit works around that 'helpful' behavior
calling .chr to convert the code to a character, or essentially do nothing in
never versions of ruby.

Also adds ye ol' ruby debugger when you're running 1.8.7.