[20170418192608] CloudFormation/ECS Events sent to SQS

This update changes the method in which Cloudformation and ECS events are received. Previously they were sent to a lambda function and saved to the app logs. Now they are sent to a SQS queue where the rack monitor will process them. The events are still visible via convox rack logs and convox logs.

The goal with this change is to reduce the number of API calls made to prevent throttling.