Add Request Spec/Fix bugs in views/spree/admin/relation_types/new.html
Relation Type Specs have been created & tested.

Achievements:
- Adding non-blank-validation and name uniqueness into Relation Type model
- Creating relation_type unit tests scenarios
- Fixing up new relation type views
- Creating relation_type integration tests
Reverting back Yaml settings
Create RelationProductDiscount model spec and some commented code for routing