Basic sanity check to verify that a `flatcc` generated reader can read binaries generated by Googles `flatc` compiler. `monsterdata_test.mon` is generated by Googles flatc compiler using the `monsterdata_test.golden` json as input and `monster_test.fbs` as schema. `monsterdata_test.json` was also copied for completeness - it apparently relates to undocumented hash attributed that converts json strings into hashes where the golden file has the correct target type with respect to the schema..