Add test for transaction exit link tracking.
Add test for transaction exit link tracking.

tadast/static,robinwhittleton/static,alphagov/static,robinwhittleton/static,tadast/static,kalleth/static,kalleth/static,kalleth/static,tadast/static,alphagov/static,robinwhittleton/static,robinwhittleton/static,kalleth/static,alphagov/static,tadast/static