No need to fnd the merge base to check change

Author: Seulgi Kim

.travis/check-change

@@ -84,8 +84,7 @@ push)
  # we can find common ancestor of master and the branch.
  echo "Branch push"
  git fetch origin master:master;
- BASE=$(git merge-base master "${TRAVIS_COMMIT}")
- COMMIT_RANGE="${BASE}...${TRAVIS_COMMIT}"
+ COMMIT_RANGE="origin/master..${TRAVIS_COMMIT}"
  fi
  ;;
 pull_request)