Make this project run as a lambda function

[claudijd]

We currently run this job as a Jenkins job, but it has no internal dependencies and thus could be pretty easily moved to something like lambda and just be a scheduled job. The only down-side would be that we'd need to sort out cred management (likely credstash), logging, and notification when failures occur (likely SES).

This means the entire thing could be code described and reduce our dependancy on pentest-auto 1.0 infra, which will not be around forever.