Eliminating the keys for use with roles attached to EC2 instances

[imarsman]

I am a bit new at this but was wondering if the keys could be omitted if a role with the proper permissions was already attached to the EC2 instance on which zaws was running. Looking at the code, it appears that execution will exit if there is no key provided. I have tended to use role assignment on EC2 instances to avoid having to worry about key vulnerability.