Attempting to use IAM role as a fallback for AWS credentials
Handle NPE for unset credentials
Use InstanceProfileCredentialsProvider for getting IAM role credentials
Merging master
Merge with master
Merge branch 'master' into iam-role
Merge branch 'master' into iam-role
Merge branch 'master' into iam-role
Merge branch 'master' into iam-role
Merge branch 'master' into iam-role
Merge pull request #5 from ericdowd/iam-role

Use IAM role as fallback when AWS credentials are not provided