autoload grpc/GPBMetadata/

composer.json

@@ -40,9 +40,9 @@
             "Database\\Factories\\": "database/factories/",
             "Database\\Seeders\\": "database/seeders/",
             "GPBMetadata\\": [
-                "GPBMetadata/"
+                "grpc/GPBMetadata/"
               ],
-            "Mint\\": "Mint/"
+            "Mint\\": "grpc/Mint/"
         }
     },
     "autoload-dev": {