t/rose-rug-brief-tour: fix broken test.

Test broken after cylc/cylc#477. See also #678.
Merge pull request #691 from matthewrmshin/fix.t/rose-rug-brief-tour

t/rose-rug-brief-tour: fix broken test.
Merge branch 'master' of github.com:metomi/rose into metomi-gh-pages