Thanks for this project and I followed the README very easily, but I think README needs some supplement for new users of AWS (like me).

While I was following that README, Before running of lambda deploy, I should create IAM users for getting aws_access_key_id and aws_secret_access_key. Nextly, I should create ~/.aws/credentials files for saving both key or just input to config.yaml (don't need to share). Finally, I should attach two policies to my IAM users, AWSLambdaFullAccess (for creating lambda function) and IAMFullAccess (perfoming iam:getUser). (I think Amazon provides more narrow polices)

Summary,
Before run lambda deploy

1. Create IAM users
2. Get aws_access_key_id and aws_secret_access_key
3. Save above keys to ~/.aws/credentials
4. Attach AWSLambdaFullAccess and IAMFullAccess
5. Run lambda deploy

Regards