Sustainable testing

@andycroll `#register` makes more sense for `User.new(user_params).register` but, as you said, wierd for a service object :smile: 

> I'm not a fan of .call, .run, .perform or .execute

let me ease you for the above, `ServiceObjects` are supposed to provide a single service hence ideally they should have one public method hence `.call` or `.execute`, etc. make sense for them because you are saying to your "service object __do the damn thing for me__ as your existence is there for just one reason". If you need another api on the same service object then it probably means your service object is not well defined or has been mutated :smile: