clear the sql counter on teardown so the GC can do it's thing

activerecord/test/active_record/test_case.rb

@@ -9,6 +9,10 @@ def setup
       cleanup_identity_map
     end
 
+    def teardown
+      ActiveRecord::SQLCounter.log.clear
+    end
+
     def cleanup_identity_map
       ActiveRecord::IdentityMap.clear
     end