Change default tokenizer to HerbertTokenizerFast

config.json

@@ -14,7 +14,7 @@
   "num_attention_heads": 12,
   "num_hidden_layers": 12,
   "pad_token_id": 1,
-  "tokenizer_class": "XLMTokenizer",
+  "tokenizer_class": "HerbertTokenizerFast",
   "type_vocab_size": 2,
   "vocab_size": 50000
 }