Use #silence_warnings from test_helper
Use #silence_warnings from test_helper

`Kernel.silence_warnings` is an ActiveSupport patch

dg1dd1ngs/haml,keithpitty/haml,dg1dd1ngs/haml,keithpitty/haml,nazar-pc/haml,macressler/haml,tangposmarvin/haml,haml/haml,macressler/haml,sideci-sample/sideci-sample-haml,stanhu/haml,haml/haml,haml/haml,nazar-pc/haml,stanhu/haml,tangposmarvin/haml,haml/haml