[joecot]

IMO one of the better ways to handle managing config and functions is using the Serverless Framework: https://serverless.com/

Your configuration and your code both live together, and can be stored in git together. You can create separate environments -- dev, staging, production, etc -- and deploy to them separately.

There aren't great options for testing in Lambda right now, and for the most part the advice I've seen is to make testable libraries, and then hook them into lambda.