The `Output#directories` attribute is no longer a "simple" list of directory paths (list of strings). Due to changes around [Line 91 of `lib/albacore/output.rb`](https://github.com/mhoyer/albacore/commit/0dcdd61912521c04ee064b4875ce56f2ee1978b2#L0L91) to store a source-target mapping instead of source only, I followed a similar way for directories as already was implemented for `Output#files`.

Thus, the `@dictionaries` attribute now is a list of 2D arrays. This asterisk was required to pass in the two-element items to the newly introduced `OutputBuilder#dir(dir, dir_to)` method.

See: http://blog.hulihanapplications.com/browse/view/45-the-asterisk-in-ruby

Simply try to remove the asterisk and watch some specs go red.