closes ruby-hyperloop#61

Author: catmando

lib/reactive_record/active_record/instance_methods.rb

@@ -3,7 +3,7 @@ module ActiveRecord
   module InstanceMethods
 
     def inspect
-      "<#{model_name}:#{ReactiveRecord::Operations::Base::FORMAT % backing_record.object_id} "\
+      "<#{model_name}:#{ReactiveRecord::Operations::Base::FORMAT % to_key} "\
       "(#{ReactiveRecord::Operations::Base::FORMAT % object_id}) "\
       "#{backing_record.inspection_details} >"
     end
@@ -173,6 +173,10 @@ def errors
       @backing_record.errors
     end
 
+    def to_key
+      @backing_record.object_id
+    end
+
     def update_attribute(attr, value, &block)
       send("#{attr}=", value)
       save(validate: false, &block)