Juju CI is updated to test the autoload-credentials changes

[Curtis Hovey-Canonical]

We saw the autoload-credential test failures this morning. The test is
strongly coupled to the prompt text. We updated the test to support
the new text, then re-ran the last failure to show there is no issue
in master

    https://bugs.launchpad.net/juju-ci-tools/+bug/1606242

-- 
Curtis Hovey
Canonical Cloud Development and Operations
http://launchpad.net/~sinzui