Datamappify::Lazy causing errors with has_many

[semmons99]

Hi again @fredwu

I'm trying to using the Datamappify::Lazy feature. However, once I start including it, things like saving break. Instead of trying to explain it in the abstract, I've created a repository that shows you the error along with the code before and after. Please take a look and let me know if I'm missing something or if I can help you fix this in any way.

https://github.com/semmons99/datamappify-test-app