Build a small automate model using factory girl

This PR builds a small automate model with the hierarchy
 DOMAINS
      NAMESPACES
          CLASS
              INSTANCES
              METHODS
e.g.
FactoryGirl.create(:miq_ae_domain, :with_small_model, :with_instances, :name => 'FRED')
FactoryGirl.create(:miq_ae_domain, :with_small_model, :with_instances,
:with_method, :name => 'BARNEY')