MAGETWO-32501: Implement Cart Service interfaces

added preference for CartInterface

Author: Serhiy Shkolyarenko

app/code/Magento/Quote/etc/di.xml

@@ -19,6 +19,7 @@
         </arguments>
     </type>
     <preference for="Magento\Quote\Api\Data\CartItemInterface" type="Magento\Quote\Model\Quote\Item" />
+    <preference for="Magento\Quote\Api\Data\CartInterface" type="Magento\Quote\Model\Quote" />
     <preference for="Magento\Quote\Api\CartItemRepositoryInterface" type="Magento\Quote\Model\Quote\Item\Repository" />
     <preference for="Magento\Quote\Api\CartRepositoryInterface" type="Magento\Quote\Model\QuoteRepository" />
     <preference for="Magento\Quote\Api\Data\CartSearchResultsInterface" type="Magento\Framework\Api\SearchResults" />