This commit moves the Amazon builders of Packer away from the Hashicorp
fork of the goamz library to the official AWS SDK for Go, in order that
third party plugins may depend on the more complete official library
more easily.
/cc @whostolebenfrog - I actually simplified things quite a bit. I added
a "uuid" global template function so it just uses that now. I renamed it
so that it is clear it is a temporary keypair.
James Nugent
Florian Noeding
Mitchell Hashimoto
Ben Griffiths