Add option to filter out internal routes

[gordysc]

You can define HapiJS routes that are only internal http://hapijs.com/api#route-configuration

This was introduced in 9.1.0: https://github.com/hapijs/hapi/commit/66730f979f05525c61e28d8fb0dca45f2004b426

However, these internal routes are showing up on blipp. It'd be a nice option to be able to hide those. Perhaps the option could be hideInternalRoutes and default to false? I'd be more than happy to make the PR for this. It would push the devDependencies up a major version from 8.x.x. to 9.x.x. Given Hapi is currently on 15, this seems like it'd be safe. Thoughts?

[danielb2]

Also maybe some kind of marker to indicate them being internal when they are displayed too