No error check when missing entity #123

If doing a permissions check on a route that may be accessed by a logged out user there is no check for the error flag.
https://github.com/feathersjs-ecosystem/feathers-permissions/blob/release/lib/index.js#L33

This causes an issue because currently I'm using permissions check in users before hooks with error false. This makes it easier than implementing it on every method except POST (which you would obviously be logged out for in the event of a new registration).

Is there some reason the error check is not implemented there?