message: Check class name string instead of checking the instance
  This fixes an issue with the newer Google's DBAPI library, which moved Row from google.cloud.bigquery._helper.Row to google.cloud.bigquery.Row, causing ImportError
diff: @@ -1200,8 +1200,7 @@ class BQEngineSpec(BaseEngineSpec):
  @classmethod
  def fetch_data(cls, cursor, limit):
  data = super(BQEngineSpec, cls).fetch_data(cursor, limit)
  - from google.cloud.bigquery._helpers import Row # pylint: disable=import-error
  - if len(data) != 0 and isinstance(data[0], Row):
  + if len(data) != 0 and type(data[0]).__name__ == 'Row':
  data = [r.values() for r in data]
  return data
  