Support schain in ZEDO adapter

modules/zedoBidAdapter.js

@@ -84,6 +84,10 @@ export const spec = {
       }
       data['placements'].push(placement);
     });
+    // adding schain object
+    if (bidRequests[0].schain) {
+      data['supplyChain'] = getSupplyChain(bidRequests[0].schain);
+    }
     return {
       method: 'GET',
       url: SECURE_URL,
@@ -154,12 +158,20 @@ export const spec = {
     } catch (e) {
       utils.logError(e);
     }
-  },
+  }
+
+};
+
+function getSupplyChain (supplyChain) {
+  return {
+    complete: supplyChain.complete,
+    nodes: supplyChain.nodes
+  }
 };
 
 function getCreative(ad) {
   return ad && ad.creatives && ad.creatives.length && find(ad.creatives, creative => creative.adId);
-}
+};
 /**
  * Unpack the Server's Bid into a Prebid-compatible one.
  * @param serverBid