Summary:
Add script auto_sanity_test.sh to perform auto sanity test
usage: auto_sanity_test.sh [new_commit] [old_commit]
Running without commit parameter will do the sanity test with the latest
and the latest 10 commit.
Test Plan: ./auto_sanity_test.sh
Reviewers: haobo, igor
Reviewed By: igor
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17397
