EntitiesDescriptor id is not required by schema.

Modelling was in correct in this case, the identifier should be able
to be nil to conform to schema.
Ensure Factories spec runs within transaction

Previously the generated specs for Factories and traits did not
run within a transaction living the database full of garbage.
Have Factory specs participate in filtering
Ensure metadata schema requirements are enforced

For IDP/SP/AA the schema has various requirements around endpoint
presence. While this was being checked by the nature of the
association that is in use these tests make the checks more explicit.
Enhance factories for metadata models

The changes here represent enhancements to model factories that where
necessary once real world use was made.

Generally this refines the relationships between models but also adds
so additional traits to support metadata use cases which the AAF is
moving towards such as eduGAIN and REFEDS entity categories.
Create and validate a basic federation

Provides an end to end test of all the SAML metadata models which
make up the metadata service.

This includes verification against eduGAIN and REFEDS
Entity Categories (research and scholarship explicitly) which impose
additional, non schema enforced, requirements over and above the
explicit specifications in use.
Speed up execution time spec

Previously the spec would take ~15s to run, now down to ~3s saving
~12s per exec by primarilly asserting against single
md:EntitiesDescriptor instance only.
Merge pull request #6 from ausaccessfed/feature/federation-wide-factory

Feature/federation wide factory