Improve ssh.ReplaceKeys

Improve ssh.ReplaceKeys

ReplaceKeys is used by the authentication worker
to write ssh keys to ~/.ssh/authorized_keys. It
merges existing keys with those added to Juju. It
checks that all keys to be written have comments, but
existing keys may not have comments. The check for key
comment is done as any keys are added to Juju so the
check in ReplaceKeys can be removed.

https://code.launchpad.net/~wallyworld/juju-core/replace-ssh-keys-fix/+merge/213406

(do not edit description out of merge proposal)

[wallyworld, 2014-03-31 05:41:33]

Please take a look.

[jameinel, 2014-03-31 10:11:30]

LGTM

maybe a comment on the test line saying "ensure that we can have some ssh keys
that don't have comments, since existing keys may not have them".

Or something along those lines.

[wwitzel3, 2014-03-31 10:29:05]

LGTM