Added partner models & interfaces
Update composer.json
Merge pull request #27 from cordoval/patch-3

Update composer.json
move cart and order related entities into Order namespace
update the tests to match the Order namespace reorganization
add a test to make sure the product ValidationOptions is called
add product ValidateOptions
remove option functionality except set and clear. It doesn't make sense to partially set options and it also prevents option validation
add some simple event dispatching
create an Event class, update interface
add setting and getting a name for the cart
move the excpetions out of the Entity namespace
allow the Product to be set when an Item is constructed
add PricingSet to entities
add pricingSet to Item
fix namespace in pricingset
updates to items concerning the pricing set
add pricing context to entities
add a test to make sure the product ValidationOptions is called
add product ValidateOptions