Make tests fail for static not found

ValidateWebsite::Core::static#test_0002_not found:
Errno::ENOENT: No such file or directory @ rb_sysopen - dev/validate-website/http://about.validator.nu/style.css
Fix Errno::ENOENT error

fix 5e057cb16d53cbfbb9621522de0a819646bebbdb

But continue to fail

ValidateWebsite::Core::static#test_0002_not found:
URI::InvalidURIError: bad URI(is not URI?): tags/développeur/public
Fix URI::InvalidURIError