Created RubyMine repo + stub classes + Price and Offer impl and unit tests
Impl cashier, customer, product and purchase + unit tests
Main + coding convention
Changed cashier to accept list of prices as requested
Added comments
Added Audit singleton
Rearranged folder structure
Clean up
Clean up /2
Removed RubyMine project files
Completed some unit tests, added currency support and other minor changes
Rubified method signatures and other parts of the code, eliminated state mutation
Corrections on operator precedence
Renamed main.rb to supermarket.rb