A gradiusbot for the Discord chat service.
Every file in the private_plugins and public_plugins folder are loaded as a module and is imported.
After every message, each public message is sent to every public_plugin, and each private message is sent to every private_plugin.
The plugin file should contain an action method that takes a Discord Message and send message callback function.
The plugin will process the message and use the callback function to send messages if needed.