title: Broadleaf commerce Api adding an item to shopping does not work
body: <p>I have followed setting up Broadleaf to make it running by following its documentation (<a href="http://docs.broadleafcommerce.org/current/REST-Tutorials.html" rel="nofollow">http://docs.broadleafcommerce.org/current/REST-Tutorials.html</a>). The setup website works fine. Howver, when I tested the Adding an item to the shopping cart REST api, I found that it caused me an error. Here is my input:</p>
  
  <p>url: localhost:8080/api/cart/2003/100?skuId=100&amp;customerId=1101
  request method: POST</p>
  
  <p>found error:[ERROR] 02:15:57 DefaultErrorHandler - An error occurred during the workflow
  org.broadleafcommerce.core.order.service.exception.RequiredAttributeNotProvidedException: Unable to add to product (100) cart. Required attribute was not provided: COLOR</p>
  
  <p>My setup environment is:
  - Broadleaf commerce 2.2
  - MySql database whose data comes from Braodleaf DemoSite.</p>