[Ruby] hoe and tests

[Timothy J. Wood]

   I packaged my gem and installed it locally, but when I do 'gem  
check -t' on the installed copy, no tests are found.  Presumably the  
issue is that there is no test_file set on the gem spec.

   Adding this to my spec_extras fixes the problem:

     :test_files => Dir[*p.test_globs]

   so maybe this should be in 'hoe'.

-tim