Since we inherit from all the required interfaces anyway, autoconfigure should
just work. No need to confuse users with all the special service tags.

This adds one config entry and injects the value into a service when the bundle gets loaded.

See the README changes for how to set the config in the symfony app.

Fixes #2

The core bundle no longer requires auth by default which means all
API endpoints can be accessed without any token now.

This adds one custom controlle which requires auth as an example.

Also adds some basic tests for all the added endpoints.