Github user ahgittin commented on the issue:
https://github.com/apache/brooklyn-docs/pull/237
actually instructions here are fine. was failing for me because i was also
setting `extraSshPublicKeyData`
seems like the combo of `TemplateOptions.authorizePublicKey(String)` and
`EC2TemplateOptions.keyPair(String)` makes jclouds fail---
