Catherine Zeta-Jones took to social media to post a very rare picture of her husband, Michael Douglas, in order to celebrate a big achievement.MORE: Catherine Zeta-Jones shares romantic selfies with husband Michael DouglasShe posted a black-and-white shot of her husband from his younger days, early into his career as an actor, as a sweet tribute to him.WATCH: Catherine Zeta Jones makes hilarious comment about Michael Douglas and family genesThe post was meant as a celebration for her husband's