Remove usage of `should` in test method names betterspecs.org/#should

It seems like the test uses a lot of `should` instead of just stating what it does, and what the purpose of the test is.

betterspecs.org/#should is properly the best description to why should is disallowed. Also its a best practice to not use should when speccing .
that is type of SerializableInterface means exactly that it has that capability of being serializable. it_is_serializable or it_gets_serialized (+1) is better than the current state of its_serialized. yeap