adapted elbas gem to handle private-IP-hostnames

[afquinn]

Adapted the instance collection to take the hostnames of both public OR private Hostnames

[lserman]

Hello, wow, this is a blast from the past!

I don't know much about how AWS deployments are working these days. What is the use case for private IP and will this change affect existing users in any way? Perhaps there are users who have instances without public IPs that are currently being ignored by this gem. If they have private IPs though, wouldn't this change how the gem functions for them?

Maybe the inclusion of private IPs can be a configuration option, or maybe the list of instances can be completely overridable by a configuration lambda that receives the instance list and returns which ones should be included.