testball: use sha256.

Library/Homebrew/test/testball.rb

@@ -2,7 +2,7 @@ class Testball < Formula
   def initialize(name="testball", path=Pathname.new(__FILE__).expand_path, spec=:stable)
     self.class.instance_eval do
       stable.url "file://#{File.expand_path("..", __FILE__)}/tarballs/testball-0.1.tbz"
-      stable.sha1 "482e737739d946b7c8cbaf127d9ee9c148b999f5"
+      stable.sha256 "1dfb13ce0f6143fe675b525fc9e168adb2215c5d5965c9f57306bb993170914f"
     end
     super
   end