nuxeo-web-ui-ftest does not find feature files

this code seems incorrect

  const separator = args.specs.lastIndexOf('/');
  const files = Finder.from(args.specs.substring(0, separator)).findFiles(args.specs.substring(separator));

If the arg.specs value is the default value ./features/*.feature, the findFiles parameter is /*.feature

This doesn't work on MS windows. *.feature however works fine