Make use of severity levels

Signed-off-by: José Valim <jose.valim@gmail.com>

activerecord/test/cases/log_subscriber_test.rb

@@ -4,6 +4,7 @@ require "active_support/log_subscriber/test_helper"
 
 class LogSubscriberTest < ActiveRecord::TestCase
   include ActiveSupport::LogSubscriber::TestHelper
+  include ActiveSupport::BufferedLogger::Severity
 
   def setup
     @old_logger = ActiveRecord::Base.logger
@@ -41,14 +42,14 @@ class LogSubscriberTest < ActiveRecord::TestCase
   end
 
   def test_basic_query_doesnt_log_when_level_is_not_debug
-    @logger.level = 1
+    @logger.level = INFO
     Developer.all
     wait
     assert_equal 0, @logger.logged(:debug).size
   end
 
   def test_cached_queries_doesnt_log_when_level_is_not_debug
-    @logger.level = 1
+    @logger.level = INFO
     ActiveRecord::Base.cache do
       Developer.all
       Developer.all