Need koa-views only only a few routes
Suppose I have a bunch of routes - /a, /b, /c, /d, /e, /f, /g ..., but only routes /a and /b will ever render any pages.

Is it better to call `app.use(views(..))` at the top of my server (before any routes are defined) OR is it better to call `app.use('/a', mount(views(...)))` - ie only at the top of the routes that need it?
