Add auth-key for node registration

Main.gd

@@ -5,6 +5,7 @@ var config = ConfigFile.new()
 var websocket_url
 var public_path
 var output_dir
+var auth_key
 var rendering = false
 signal finished_rendering
 
@@ -14,6 +15,7 @@ func _ready():
 	websocket_url = config.get_value("core", "websocket_url")
 	public_path = config.get_value("core", "public_path")
 	output_dir = config.get_value("core", "output_dir")
+	auth_key = config.get_value("core", "auth_key")
 	print("Starting render node")
 	
 	var directory = DirAccess.open(".")