Add an alias for test-unit with older versions of RubyGems

Author: aycabta

test/rdoc/test_rdoc_rubygems_hook.rb

@@ -9,6 +9,9 @@ class TestRDocRubygemsHook < Gem::TestCase
  unless method_defined?(:assert_path_not_exist)
  alias assert_path_not_exist refute_path_exists
  end
+ unless method_defined?(:assert_raise)
+ alias assert_raise assert_raises
+ end
 
  def setup
  super