Proper attachment structure

Author: Renat Zubairov

lib/actions/write.js

@@ -47,7 +47,10 @@ function processAction(msg) {
                 rowCount
             });
             const fileName = messageToEmit.id + '.csv';
-            messageToEmit.attachments[fileName] = signedUrl.get_url;
+            messageToEmit.attachments[fileName] = {
+                "content-type": "text/csv",
+                url: signedUrl.get_url
+            };
             console.log('%j', messageToEmit);
             signedUrl = null;
             rowCount = 0;