Add ActiveJob serializer for Money objects

[sunny]

This change adds a serializer so that ActiveJob can enqueue jobs with Money arguments out of the box.

I’ve been using the same serializer in a production app for a while, and think this would help users not have to create their own serializer.

See also: Documentation for Active Job serializers.

[sunny]

Hi there! Thanks for maintaining money-rails. It’s great to see some activity here 🎉

Can we get some reasoning behind closing this? 🙏🏻

[semmons99]

errant automation, let's reopen and review

[semmons99]

cannot re-open, can you submit another that I can merge for ya?

[sunny]

Sure thing! --^