add tests for serialization bug
add tests for serialization bug

Gregory-Howard/spaCy,explosion/spaCy,raphael0202/spaCy,raphael0202/spaCy,recognai/spaCy,raphael0202/spaCy,banglakit/spaCy,spacy-io/spaCy,spacy-io/spaCy,oroszgy/spaCy.hu,spacy-io/spaCy,recognai/spaCy,oroszgy/spaCy.hu,recognai/spaCy,oroszgy/spaCy.hu,explosion/spaCy,Gregory-Howard/spaCy,explosion/spaCy,wbwseeker/spaCy,aikramer2/spaCy,wbwseeker/spaCy,aikramer2/spaCy,Gregory-Howard/spaCy,oroszgy/spaCy.hu,honnibal/spaCy,aikramer2/spaCy,raphael0202/spaCy,wbwseeker/spaCy,banglakit/spaCy,recognai/spaCy,explosion/spaCy,Gregory-Howard/spaCy,honnibal/spaCy,banglakit/spaCy,spacy-io/spaCy,Gregory-Howard/spaCy,wbwseeker/spaCy,banglakit/spaCy,spacy-io/spaCy,wbwseeker/spaCy,explosion/spaCy,wbwseeker/spaCy,raphael0202/spaCy,oroszgy/spaCy.hu,recognai/spaCy,oroszgy/spaCy.hu,aikramer2/spaCy,spacy-io/spaCy,aikramer2/spaCy,banglakit/spaCy,aikramer2/spaCy,recognai/spaCy,honnibal/spaCy,banglakit/spaCy,explosion/spaCy,Gregory-Howard/spaCy,honnibal/spaCy,raphael0202/spaCy