Print an error to console when fails to deliver a log event to Loggly

lib/winston-loggly.js

@@ -145,6 +145,9 @@ Loggly.prototype.log = function(meta, callback) {
   //
   function logged(err, result) {
     self.emit('logged');
+    if (err) {
+      console.error('Loggly Error:', err);
+    }
     callback && callback(err, result);
   }