def register(subject, schema, **params)
      lookup_subject_schema(subject, schema)
    rescue Excon::Errors::NotFound
      register_without_lookup(subject, schema, params)
    end
def register(subject, schema, **params)
      lookup_subject_schema(subject, schema)
    rescue Excon::Errors::NotFound
      register_without_lookup(subject, schema, params)
    end
Override register to first check if a schema is registered by fingerprint
 Also, allow additional params to be passed to register.