Explicitly disabled warnings in rake

Wasn't working before

Author: iainbeeston

Rakefile

@@ -15,7 +15,7 @@ end
 Rake::TestTask.new do |t|
   t.libs << "."
   # disabled warnings because addressable 2.4 has lots of them
-  # t.warning = true
+  t.warning = false
   t.verbose = true
   t.test_files = FileList.new('test/*_test.rb')
 end