FIX: AWS S3 errors don't necessarily include a message

* If the error doesn't have a message, the class name will help
* example:
  before: "Failed to download #{filename} because "
  after: "Failed to download #{filename} because Aws::S3::Errors::NotFound"

lib/s3_helper.rb

@@ -230,7 +230,7 @@ class S3Helper
   def download_file(filename, destination_path, failure_message = nil)
     object(filename).download_file(destination_path)
   rescue => err
-    raise failure_message&.to_s || "Failed to download #{filename} because #{err.message}"
+    raise failure_message&.to_s || "Failed to download #{filename} because #{err.message.length > 0 ? err.message : err.class.to_s}"
   end
 
   def s3_client