message: Re-enable tests for tf.einsum().
  These tests check that tf.einsum() is equivalent to np.einsum().
  At one point, some of them were failing because of a bug in
  np.einsum() in an old version of numpy.  This bug has been fixed,
  so we can re-enable the tests now.
diff: @@ -240,7 +240,7 @@ class EinsumTest(test.TestCase):
  'aef,fbc,dca->bde',
  'iJ,Jk->ik',
  'iJ,Ki->JK',
  - 'iJk,Jklm->Jk'
  + 'iJk,Jklm->Jk',
  'ij, jk, kl -> il',
  'a, ab, abc -> abc',
  'ab, ab, cd, cd, ef, ef -> ',
  @@ -280,7 +280,7 @@ class EinsumTest(test.TestCase):
  dim_mismatch_cases = [('ijk,jkl->il', [(2, 3, 4), (3, 5, 6)])]
  - def disabled_test_simple(self):
  + def test_simple(self):
  for case in self.simple_cases:
  self.run_test(case)
  