'Verify that In variable grows with user input (GH-284)'

def test_In_variable(self):

    oldlen = len(ip.user_ns['In'])
    ip.run_cell('1;', store_history=True)
    newlen = len(ip.user_ns['In'])
    self.assertEqual((oldlen + 1), newlen)
    self.assertEqual(ip.user_ns['In'][(-1)], '1;')
