Updated gcs_eval_checkpoints.py to save tokenizer if it is missing from checkpoint directory
Fixed wrong directory when moving to eval folder. Previously it would save model weights into checkpoint-xxx and not run_name/checkpoint-xxx within GCS_MODEL_EVAL_DIR. We now fix it to save to run_name/checkpoint-xxx
checkpoint-xxxand notrun_name/checkpoint-xxxwithinGCS_MODEL_EVAL_DIR. We now fix it to save torun_name/checkpoint-xxx