Function router 

fn router(state: Arc<RwLock<StateRelayServerState>>) -> Router

Build the relay server router. Tide-disco registered api under three stacked major API versions (v1, v2, v3) with identical handlers for every route except lateststate; requests with no version prefix were redirected to the latest (v3). We reproduce that by serving the same handlers at the unversioned and all three /v{1,2,3} paths, and only special-casing lateststate per version.