Bump gds-api-adapters to 4.2.0
Add travel-advice as a supported format
Fix test to check an "unfriendly" URL parameter

This test no longer fails due to the additional
URL escaping added in gds-api-adapters 4.2.0

I still think it's a good idea to have this test
to make sure we don't get any other unexpected 
behaviour in the app - so here the request is 
stubbed to return a 404.
Display a travel advice edition from the content API