No fake valid tosca type in parser for test in translator

[Sahdev Zala]

For test purpose, it would be great to create a fake TOSCA type as valid type and in the heat-translator this type will be used to test unsupported type for translation purpose. The current test we have around loadbalancer in translator can't be there permanently. Once translation support is enabled in future, this test (test_translate_unsupported_tosca_type) will fail, so it's better to replace it with permanent fake type with the newer release of tosca parser.