initial commit of PricingElement
add interfaces for proccesing and getting the processed value
add interface to PricingContext for the quantity of items
tests for updates in interface
Merge pull request #17 from iampersistent/pricing

updates to pricing interfaces and additional tests
fix failing test due to unimplemented quantity accessors and default to 1
== --> === on the very off chance to be 0
Merge pull request #21 from cordoval/pricing

fix failing test due to unimplemented quantity accessors and default to 1
Merge pull request #28 from vespolina/pricing

Merge Pricing into refactoring