Provide an option to skip the authorized_keys

[toby-sutor]

There are legit use-cases where a user might not want to rely on the authorized_keys files. During https://github.com/elastic/ansible-elastic-cloud-enterprise/issues/15 a change was implemented, which allows to look at two different locations for a file as well as to provide a custom path. However, the Ansible task is failing if neither of those values are available.

Would it be possible to make those parameters optional and to not fail if they are unavailable, as requested in the above issue Or at least not fail if no keys are defined ?? The current workaround is to provide mock key files which is not ideal. Thank you.