PRIPAD-5148 Allow nested starting dir in route

The routing functionality provided in standard HockeyKit assumes that the setup will be:
`host.com/bundle_id/ios/`. Ideally we shouldn't be tied to starting at `bundle_id`.

By default routes are split by `/` and are then further broken apart in the format of `:key@regex_value`. This prevents any complex routing from taking place. I've swapped the router out for one that uses named regex capture groups instead of the custom key/value matchers. This allows us to nest directories as deep as required, and also requires less code to parse as it uses built in functionality.