Provide tagging interface for AwsManaged resources

[hartmans]

We need to be able to provide rich tags beyond just names for Carthage managed resources. Examples include:

• ownership information so billing can be broken out
• Interfacing to specificic provisioning systems that depend on tags
• Tracking which Carthage layout created a resource for orphan detection from the deployment engine See #12 for related work. cc: @srak289