updates for working with new awsbox & route53

Some of this is overkill, but some is needed for route53. Review changes to to latest_sha.js with https://github.com/mozilla/browserid_deployer/compare/upgrade_awsbox_for_route53?w=1

Also see https://github.com/mozilla/awsbox/pull/99, which oddly is needed to pick up nice-route53@0.3.3

- made the deploy hostname, repo, branch and some others configurable via
  environment (so I could test changes without changing
  deployer.personatest.org).
- probably went too far on making this configurable ;-)
- initialize aws.createClients so vm.{list,destroy} work correctly
- improved some error messages to help log debugging
- changed lib/latest_sha.js to lookup NS (instead of hard-coded zerigo NS)
- upgraded native-dns to current to pick up a bug fix for running on osx
- added missing dep `temp@0.6.0`, and new dep nice-route53@0.3.3
- bumped the version to 0.0.2 fwiw