support for multi worker #23
Description
Fluentd v0.14.12 or later supports multi process workers.
https://www.fluentd.org/blog/fluentd-v0.14.12-has-been-released
but, this plugin was errored like this.
2019-06-19 11:26:43 +0900 [error]: config error file="/etc/td-agent/td-agent.conf" error_class=Fluent::ConfigError error="Plugin 'rewrite' does not support multi workers configuration (Fluent::Plugin::RewriteOutput)"
I know that adding multi_workers_ready? method will result in no error message.