Comment 2 for bug 1588403

Basic problem seems to be the naming of the file under /usr/share/bash-completion/completions/ - currently the juju 2.0 packages have it as 'juju2' which bash won't invoke for the `juju` name. However, the script is not (yet) relevantly different from the juju 1.25 bash completion, so older versions still existing will make it work as expected.