Add test for preventing fetches for standard classes / properties

[joepio]

AtomicServer should not have to do fetch any properties / classes by default, all need to be included. Currently, that is not the case. Every once in while we forget to add a Class / Property to default_base_models.json. When atomicserver.dev goes down, that means these properties become unavailable, which means that new servers can miss essential classes. We can't have that.

I think we should add a test for this. Not quiete sure how this should be implemented. @Polleps do you have ideas?