Use implicit to_s for root logger

lib/passwordstate.rb

@@ -12,7 +12,7 @@ module Passwordstate
   end
 
   def self.logger
-    @logger ||= Logging.logger[name].tap do |logger|
+    @logger ||= Logging.logger[self].tap do |logger|
       logger.add_appenders Logging.appenders.stdout
       logger.level = :warn
     end