test_parser.rb: tempfile

* test/rss/test_parser.rb (RSS::TestParser#setup): use temporary file,
  should not use fixed path working files.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38884 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-01-20

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38885 b2dd03c8-39d4-4d8f-98ff-823fe69b080e