[this line](https://github.com/awslabs/aws-lambda-rust-runtime/blob/fd2ea235f4adb166422ca5b612c4a1a42a626daa/lambda-runtime/src/lib.rs#L124) makes the process exit with status 1 when the request body is malformed (e.g. there are missing fields). it should instead send back an `EventErrorRequest` with the appropriate error details and continue processing
