Answer span mismatch

[t-li]

Hi, Great work! I was trying to use the Hotpot QA in squad 2 format, but found there are some span mismatch errors.

For instance, in the dev set the question with id (HotpotQA_q_5abfa9745542997ec76fd426) the first answer candidate ("The Big Bang Theory") has start 209 but it's actually 204.