Added factory for discount schemes
spec for group discount behaviour
Green step, group discount returns price modification
Refactor step
More refactoring
Refactored names for legibility
Merged kheldysh suggestions, fixed small errors
Added stopper for over counting prices
Refactored factory names
More focused specs on application of discount
Specified relocation between product and group discount
Refactored to use names subject
Slight reordering of items in product
Added association specs
Red step, cart integration
Fixed comparison between Fixnum and String
Refactored test to correctly set associations
Green step, implemented modifying price with discount
Added dot files for ruby-version and gem set to introduce compatibility with other than rvm
Moved versions and gem set to be read form the corresponding files