Prepare for transaction done pages
Remove "find out more" box

It's not longer necessary and will obstruct parts of the image
provided by DWP.
Update <title> to be same as <h1> for page
Update workplace pensions image to use Greggs location
Update the YouTube URL for the Workplace Pensions campaign
Refactor travel advice filtering

To expose methods to test
Intial batch of unit tests for travel advice
Add a TestRunner that can be used in-browser
Add more tests for public methods

Also refactor source to allow testing.
Add tests for updateCounter and filterListItems

Also includes refactoring of other tests to avoid
false-positives.