Update cache invalidation tests for topic association
Update cache invalidation tests for topic association

We used to invalidate the cache based on the published time of a topic's
policies' associated editions. Now that topics are associated directly
with editions, we don't need to go via the topic.

hotvulcan/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,askl56/whitehall,askl56/whitehall,ggoral/whitehall,robinwhittleton/whitehall,alphagov/whitehall,alphagov/whitehall,ggoral/whitehall,alphagov/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,ggoral/whitehall,askl56/whitehall,alphagov/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,robinwhittleton/whitehall,ggoral/whitehall