Nice work! Just signed up and am testing sending some AWS Alarms for Elastic Beanstalk via a template. One problem I've come across straight away is that your templating engine doesn't seem to be able to handle JSON arrays.

The EB notification JSON body that gets POSTed by the SNS Topic contains a Record[] structure with the messages, and when I try to setup {{ Records[0].Sns.Message }} in the template, I am getting a "template: notification-content:2: unexpected bad character U+005B '[' in command" error.