fixing tests final nice-up

app/models/lti_parameter.rb

@@ -1,4 +1,8 @@
 class LtiParameter < ActiveRecord::Base
+  belongs_to :consumer, foreign_key: "consumers_id"
+  belongs_to :exercise, foreign_key: "exercises_id"
+  belongs_to :external_user, foreign_key: "external_users_id"
+
   scope :lis_outcome_service_url?, -> {
     where("lti_parameters.lti_parameters ? 'lis_outcome_service_url'")
   }