Add example header

lm_eval/tasks/quac.py

+"""
+QuAC: Question Answering in Context
+https://arxiv.org/abs/1808.07036 
+
+@article{choi2018quac,
+  title={Quac: Question answering in context},
+  author={Choi, Eunsol and He, He and Iyyer, Mohit and Yatskar, Mark and Yih, Wen-tau and Choi, Yejin and Liang, Percy and Zettlemoyer, Luke},
+  journal={arXiv preprint arXiv:1808.07036},
+  year={2018}
+}
+"""
+
 import json
 import os
 from lm_eval.base import Task
 from ..utils import sh
 
 
-class QuAC(Task):    
+class QuAC(Task):
+    VERSION = 0
+
     def __init__(self):
         super().__init__()