Update Plugins to keep a reference to the Bot object instead of server_config

Plugins now use Bots instead of server_configs, this is useful for
checking the currently joined channels and perhaps using the connection
when there isn't one available in the current method.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

omnibot/bot.py

@@ -16,14 +16,13 @@ log = logging.getLogger(__name__)
 class Bot:
     def __init__(self, server_config: ServerConfig):
         self.__server_config = server_config
+        self.__channels: Set[str] = set()
+        self.__quitting = asyncio.Event()
         self.__plugins = [
-            plugin.load_plugin(server_config, config)
+            plugin.load_plugin(self, config)
             for config in server_config.plugins
             if config.get("enabled", True)
         ]
-        # TODO - this may not be needed
-        self.__channels: Set[str] = set()
-        self.__quitting = asyncio.Event()
 
     @property
     def server_config(self) -> ServerConfig: