#40 - ASGARD-907 - IAM Credentials, with Key Management Service for laptops

Now there are additional ways to get AWS credentials, including some of the ones built into Amazon’s common usage patterns (system properties, environment variables, instance metadata IAM profile), and some legacy methods some Asgard machines use (Grails configuration, local secret files, remote secret files over SSH), and a new method of getting credentials from a remote key management system over SSL with a signed local key store.

Instead of going through SecretService to create an AWSCredentials object, Asgard now uses an AWSCredentialsProviderChain to initialize amazon client objects. The provider chain goes through the seven available algorithms for getting credentials until it finds one that works.