* gems/bundled_gems: Upgrade to test-unit 3.0.8. assert_throw and
  assert_nothing_thrown in test-unit 3.0.7 were broken by
  UncaughtThrowError change introduced in Ruby 2.2.0
  preview2. These assertions in test-unit 3.0.8 work well with
  UncaughtThrowError in Ruby 2.2.0 preview2.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48787 b2dd03c8-39d4-4d8f-98ff-823fe69b080e