Add backwards-compatibility spec


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@668942 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/rb/spec/spec_helper.rb b/lib/rb/spec/spec_helper.rb
index 9a573fe..fc15741 100644
--- a/lib/rb/spec/spec_helper.rb
+++ b/lib/rb/spec/spec_helper.rb
@@ -1,6 +1,11 @@
 require 'rubygems'
 require 'spec'
 
+# turn on deprecation so we can test it
+module Thrift
+  DEPRECATION = true
+end
+
 require File.dirname(__FILE__) + '/../lib/thrift'
 
 class Object