add imds asg target lifecycle hook by pete911 · Pull Request #825

add imds asg target lifecycle hook by pete911 · Pull Request #825 · aws/aws-node-termination-handler

Issue #, if available:
ASG target lifecycle hook is already available in instance metadata service. This pull request adds it to IMDS option.
Description of changes:
Adding ASG Termination Lifecycle Hook to IMDS Processor.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.