Implement rate limiting to harden against hacking

[eddyystop]

This continues feathersjs-ecosystem/feathers-authentication-management#85

luc.claustres [5:21 AM]
And about rate limiting this can be implemented easily using hoojs or low-level app control over requests

I would think this is something which should be implemented for any service not just this repo. I've therefore created this issue feathers-plus/generator-feathers-plus#100