message: [sqllab] fix unexpected keyword argument 'ignore_nan'
diff: from __future__ import absolute_import, division, print_function, unicode_literals
  from datetime import datetime
  -import json
  import logging
  from time import sleep
  import uuid
  from celery.exceptions import SoftTimeLimitExceeded
  from contextlib2 import contextmanager
  +import simplejson as json
  import sqlalchemy
  from sqlalchemy.orm import sessionmaker
  from sqlalchemy.pool import NullPool
  