message: Update _check_shape to accept six.integer_types instead of int
  Currently _check_shape requires that a shape be an `int` or sequence of `int`s.  This CL allows `six.integer_type`s so now (1L,) would be a valid shape.
diff: @@ -2829,7 +2829,7 @@ def _check_shape(shape, key):
  shape = [shape]
  shape = tuple(shape)
  for dimension in shape:
  - if not isinstance(dimension, int):
  + if not isinstance(dimension, six.integer_types):
  raise TypeError('shape dimensions must be integer. '
  'shape: {}, key: {}'.format(shape, key))
  if dimension < 1:
  