message: Fix failing test in python 3 where by default byte (instead of string) is used
diff: @@ -431,6 +431,12 @@ def make_csv_dataset_v2(
  dataset = dataset.shuffle(len(filenames), shuffle_seed)
  # Clean arguments; figure out column names and defaults
  + def gzip_file_io_open(filename, mode):
  + # By default, gzip will open in byte mode which will
  + # not work with csv.reader so we create a wrapper to
  + # append `t`.
  + mode = mode + "t" if "t" not in mode else mode
  + return gzip.open(filename, mode)
  if column_names is None or column_defaults is None:
  # Find out which io function to open the file
  file_io_fn = file_io.FileIO
  @@ -439,7 +445,7 @@ def make_csv_dataset_v2(
  if compression_type_value is None:
  raise ValueError("Received unkown compression_type")
  if compression_type_value == "GZIP":
  - file_io_fn = gzip.GzipFile
  + file_io_fn = gzip_file_io_open
  elif compression_type_value == "ZLIB":
  raise ValueError(
  "compression_type (%s) is not supported for probing columns" %
  