configure authorized_keys locally for --allinone

When running in --allinone mode, this patch creates a local ScriptRunner
rather than a remote ScriptRunner, which permits the authorized_keys
file to be configured even if PasswordAuthentication is disabled in
/etc/ssh/sshd_config.

Closes: rhbz#1111705
        (https://bugzilla.redhat.com/show_bug.cgi?id=1111705)

Change-Id: I728f507bf0a38e75b8e981864253718afa200ca1