Remove 3 from json file

model-data/archive_books.json

@@ -18,6 +18,6 @@
   "train_data" : "archive_books/dataset/train",
   "eval_data" : "archive_books/dataset/eval",
   "classes_file" : "archive_books/dataset/classes.txt",
-  "model_output_dir" : "archive_books/book_model3",
+  "model_output_dir" : "archive_books/book_model",
   "gpu" : "0"
 }