Do not require that access credentials be specified (this allows IAM roles to be used if they are available)
Merge branch 'evertrue/eherot/support_iam_roles' of https://github.com/evertrue/aws_security into evertrue-evertrue/eherot/support_iam_roles

Conflicts:
	libraries/ec2.rb
	providers/group.rb
Merge branch 'evertrue-evertrue/eherot/support_iam_roles'
Merge branch 'master' of github.com:SearchSpring/aws_security