Test workflows should pass `cylc lint`

[wxtim]

Describe the bug if you run

for f in $(find tests/functional/ -name flow*.cylc -exec dirname {} \;); do cylc lint $f -r style; done

A non-trivial set of workflow definitions in the test battery fail linting.

Pull requests welcome! This is an Open Source project - please consider contributing a bug fix yourself (please read CONTRIBUTING.md before starting any work though).