Require pagination parameters #363

Currently, AuthX follows the Relay Connection spec to support pagination, and supports unbounded requests when both first and last are omitted. Introducing a "default" limit is therefore a breaking change, as would be changing that default in the future.

I'd like to suggest requiring a value be present in either first or last. This is also a breaking change, but one that breaks things up front, as opposed to producing unexpected results some of the time. This also forces front-end and client developers to address pagination, instead of allowing it to be swept under a hope that the default is always sufficient.