Introduce TestProf::FactoryDefault:
https://github.com/test-prof/test-prof/blob/master/docs/recipes/factory_default.md

It allows us to avoid cascading factories problem by creating a
default factory:

let(:project) { create_default(:project) }

Next created factory that has project as an association will use
the default record instead of creating a new one.

In combination with let_it_be we'll also avoid creating multiple
records for a test suite