Update Model to Reflect Promotions

[tv547]

As a marketing manager I need a resource that is a representation of a special promotion or sale that is running against a product or perhaps the entire store So that a promotion can be applied

Details and Assumptions

• Will be updated off current model

• Some examples are "buy 1 get 1 free", "20% off", etc. Discount promotions usually apply for a given duration (e.g., sale for 1 week only)."

  Acceptance Criteria

  
  Given the model
  When I run the model
  Then the model returns promotions

[tv547]

This was based on the feedback we received from John on the last hw