Add info on Eloquent relations to readme

[thomaswelton]

Add info on how to update your models to include the eloquent relations needed.
Or maybe look to see if I can make my own class that extends the consumers User model where I specify the methods that associate needs avoding the need to end users to update their models

[thomaswelton]

Ok, so for the current associate and login methods having elouquent relations isn't needed at all.
I can do the DB updates and deletes by writing my own queries instead of the eloquent relation builder doing it.