Parse Lambda log messages

[asprouse]

This PR parses the Lambda usage report log messages. Perhaps there needs to be an environment variable to disable this behavior but it would seem that most people use this function to integrate with Lambda

[ghost]

@asprouse sorry for the delay in getting back to you on this.

Great work and I agree this is something most users would want and expect.

I only have one request, which is to namespace all custom contextual values under lambda. Right now we have lambda_start, lambda_end, etc., but I think it would be cleaner and more intuitive to have them all under lambda unless you have a specific use case in mind for the different event types.

Ultimately I think we will include lambda as a known context in our schema, but this is a good solution for the interim.

[ghost]

@asprouse scratch what I said before. We will be making schema changes related to lambda and then update this code accordingly.

[asprouse]

@carkmorwin roger that. Let me know when the when the new version drops.