Data science 20141007 rc

Revisions based on Pull Request: https://github.com/jmmastey/level_up_exercises/pull/150

-clean up errors with main file
-add test_no_winner json data and tests
-convert main.rb into a Results class which takes the calculations from Dataset and wraps in some nice output
-using Hirb gem to format the console output
You can replace this code block with `raise_error(ABAnalyzer::InsufficientDataError)`.