Fix trader existence check

Author: cbovis

src/traders/check-trader-exists.js

@@ -3,7 +3,7 @@ const elasticsearch = require('../util/elasticsearch');
 const checkTraderExists = async address => {
   const response = await elasticsearch.getClient().count({
     index: 'fills',
-    body: { query: { term: { trader: address } } },
+    body: { query: { term: { traders: address } } },
   });
 
   return response.body.count > 0;