去除Rake里面warning

diff --git a/Rakefile b/Rakefile
index 554937b..dc2dcf0 100644
--- a/Rakefile
+++ b/Rakefile
@@ -5,6 +5,7 @@ require 'rake/testtask'
 Rake::TestTask.new do |t|
   t.pattern = 'spec/**/*_spec.rb'
   t.libs    << 'spec'
+  t.warning = false
 end

 task default: :test