AR::Integration must be included after AM::Conversion

Integration's definition of #to_param must override
Conversion's. Otherwise, there is a regression from
3.1 in the behavior of a non-persisted AR::Base instance
which nevertheless has an id.

activerecord/lib/active_record/model.rb

@@ -74,9 +74,9 @@ module ActiveRecord
     include Inheritance
     include Scoping
     include Sanitization
-    include Integration
     include AttributeAssignment
     include ActiveModel::Conversion
+    include Integration
     include Validations
     include CounterCache
     include Locking::Optimistic

activerecord/test/cases/base_test.rb

@@ -1684,6 +1684,12 @@ class BasicsTest < ActiveRecord::TestCase
     assert_kind_of String, Client.first.to_param
   end
 
+  def test_to_param_returns_id_even_if_not_persisted
+    client = Client.new
+    client.id = 1
+    assert_equal "1", client.to_param
+  end
+
   def test_inspect_class
     assert_equal 'ActiveRecord::Base', ActiveRecord::Base.inspect
     assert_equal 'LoosePerson(abstract)', LoosePerson.inspect