message: Fix function test to trigger and catch correct exception
  In v1 testInputSignatureForFunctionWithNonTensorInputsNotAllowed was
  raising a TypeError when it should have triggered a ValueError. This
  was due to the signature being invalid. Once the signature is fixed the
  test works in both v1 and v2 mode.
diff: @@ -1301,7 +1301,6 @@ class FunctionTest(test.TestCase, parameterized.TestCase):
  defined.get_concrete_function(
  tensor_spec.TensorSpec(shape=(3,), dtype=dtypes.float32))
  - @test_util.run_deprecated_v1
  def testInputSignatureForFunctionWithNonTensorInputsNotAllowed(self):
  def foo(a, training=True):
  @@ -1310,10 +1309,16 @@ class FunctionTest(test.TestCase, parameterized.TestCase):
  else:
  return -1.0 * a
  - signature = [tensor_spec.TensorSpec([], dtypes.float32)] * 2
  + signature = [
  + tensor_spec.TensorSpec([], dtypes.float32),
  + tensor_spec.TensorSpec([], dtypes.bool),
  + ]
  defined = def_function.function(foo, input_signature=signature)
  a = constant_op.constant(1.0)
  - with self.assertRaises(TypeError):
  + with self.assertRaisesRegexp(
  + ValueError,
  + 'When input_signature is provided, all inputs to '
  + 'the Python function must be Tensors.'):
  defined(a, training=True)
  def testInputSignatureWithKeywordPositionalArgs(self):
  