Merge branch 'rs-fix-application-helper-specs' into 'master'

Fix ApplicationHelper specs

On current `master` if you run these specs by themselves, they fail. I have no idea why they work when run with other specs, but now they work all the time.

- Use the `helper` object, as per RSpec 3 standards
- Use `assign` to assign instance variables that helpers expect
- Add `StubConfiguration` support module

See merge request !906