Feature [--migrate]: Change migrate script tests to have jest snapshots

[pksjce]

Do you want to request a feature or report a bug?
Feature

What is the current behavior?
Currently we have a custom testing workflow where we compare hardcoded output config to the transformed output. This is tedious as we have manually update output conifgs.

What is the expected behavior?
It would much easier and nicer to have verified jest snapshots and not have to hardcode output test config

[pksjce]

I think this was fixed by #40