(PUP-3644) Move urls to v3

This removes the "v1" HTTP API, which mounted
all of the various Puppet endpoints at "/" on the webserver.

In its place we now have the "v3" API, which includes
the versioned "/v3" prefix for all of the indirected URLs.
@rlinehan I'm pretty sure the answer is 'yes', but my memory is rusty--we have some test coverage that validates that this will successfully block access if auth.conf doesn't match up with the request, right?