added dedicated registrant model

app/models/domain.rb

@@ -7,7 +7,7 @@ class Domain < ActiveRecord::Base
   paginates_per 10 # just for showoff
 
   belongs_to :registrar
-  belongs_to :registrant, class_name: 'Contact'
+  belongs_to :registrant
 
   has_many :domain_contacts, dependent: :destroy
   has_many :admin_domain_contacts

app/models/epp/domain.rb

@@ -72,8 +72,9 @@ class Epp::Domain < Domain
 
   def attach_default_contacts
     return if registrant.blank?
-    tech_contacts  << registrant if tech_domain_contacts.blank?
-    admin_contacts << registrant if admin_domain_contacts.blank? && registrant.priv?
+    regt = Registrant.find(registrant.id) # temp for bullet
+    tech_contacts  << regt if tech_domain_contacts.blank?
+    admin_contacts << regt if admin_domain_contacts.blank? && regt.priv?
   end
 
   # rubocop: disable Metrics/PerceivedComplexity
@@ -84,10 +85,9 @@ class Epp::Domain < Domain
 
     code = frame.css('registrant').first.try(:text)
     if code.present?
-      oc = Epp::Contact.find_by_epp_code(code).try(:id)
-
-      if oc
-        at[:registrant_id] = oc
+      regt = Registrant.find_by(code: code)
+      if regt
+        at[:registrant_id] = regt.id
       else
         add_epp_error('2303', 'registrant', code, [:registrant, :not_found])
       end

app/models/registrant.rb

@@ -0,0 +1,6 @@
+class Registrant < Contact
+  # epp_code_map is used during epp domain create
+  def epp_code_map
+    {}
+  end
+end