use state transformer in logger plugin (#310)

src/plugins/logger.js

@@ -28,9 +28,9 @@ export default function createLogger ({
         console.log(message)
       }
 
-      console.log('%c prev state', 'color: #9E9E9E; font-weight: bold', prevState)
+      console.log('%c prev state', 'color: #9E9E9E; font-weight: bold', transformer(prevState))
       console.log('%c mutation', 'color: #03A9F4; font-weight: bold', formattedMutation)
-      console.log('%c next state', 'color: #4CAF50; font-weight: bold', nextState)
+      console.log('%c next state', 'color: #4CAF50; font-weight: bold', transformer(nextState))
 
       try {
         console.groupEnd()