Add e2e test to ensure repositoryPathPattern works

Created by: mrnugget

This automates release test grid item 15.1 When repositoryPathPattern is configured, paths from the full long name will redirect to the configured name. Extensions will function with the configured name., except for the "Extensions" part.

This was fun 🙂

@nicksnyder What do you think about this for automating the release testing? This test certainly has a cost (new (although tiny) repo to clone, lots of page loads, etc.), but it's still a ton faster than what I did for 2 times now 😉