Add a listDirs method that lists folders in a given directory.

[mhkeller]

From kestrel-cli: ajam/kestrel-cli@221a7b0

Also supports optional hidden dirs

function getDirectories(srcpath, opts) {
  return fs.readdirSync(srcpath).filter(function(file) {
    var is_directory = fs.statSync(path.join(srcpath, file)).isDirectory()
    // Test for folders that start with a dot
    if (is_directory && opts && opts.excludeHidden) {
      is_directory = !/^\./.test(file)
    }
    return is_directory;
  });
}

[mhkeller]

This has been implemented as flags on readdirFilter in 1.0.0. See changelog for details