Custom permalinks for articles

I'm looking to move over a site which has blog posts with permalinks that are built from the category of the post and post title instead of using the date. For example:

/posts/ruby-on-rails/a-look-at-decorators-and-presenters

Where **ruby-on-rails** is the category and **a-look-at-decorators-and-presenters** is the article's title.

Is it possible to replicate this using permalinks with middleman-blog currently?