Force version of nice-route53 to new 0.3.3

There was a bug in nice-route53 about updating A records
  https://github.com/chilts/nice-route53/issues/1

@chilts pushed a new version to npmjs.org, but for reasons I don't get, `npm
install awsbox` is installing the previous `0.3.2` version.

So, this change forces the version to `0.3.3` (not `0.3.x`).