Root device; ebs vs instance-store

[mal]

Would it be possible to add this as a column? Until now I've been relying on the "Instance Storage" column, but it seems some of the newer instance types (h1 and i3 at least) have Instance Storage but actually require an EBS root device (and an AMI that supports that).

Also huge thanks for this project, it's saved me so much time and grief over the years!