'Prove attributes not in the schema pass-through.'

def test_attributes_passthrough_key(self):

    stack = utils.parse_stack(self.template)
    snip = stack.t.resource_definitions(stack)['deploy_mysql']
    resg = sd.SoftwareDeploymentGroup('test', snip, stack)
    nested = self.patchobject(resg, 'nested')
    server1 = mock.MagicMock()
    server2 = mock.MagicMock()
    nested.return_value = {'server1': server1, 'server2': server2}
    server1.FnGetAtt.return_value = 'attr1'
    server2.FnGetAtt.return_value = 'attr2'
    self.assertEqual({'server1': 'attr1', 'server2': 'attr2'}, resg.FnGetAtt('some_attr'))
    server1.FnGetAtt.assert_has_calls([mock.call('some_attr')])
    server2.FnGetAtt.assert_has_calls([mock.call('some_attr')])
