Log Message:
Update ruby-sass to 3.4.22.

3.4.22 (28 March 2016)

    * Sass now runs without warnings when running ruby with code style
      warnings enabled.

    * Sass no longer watches the current working directory unless it is on
      the load path or the files being compiled are in the current working
      directory. This was causing performance issues for users with large
      numbers of files in their project directory. Issue #1562, Issue #1966,
      Issue #2006.

    * sass-convert now accepts a -q and --quiet option to disable ouput
      while it is running.

    * Fixed a bug in sass-convert when recursively processing CSS files into
      Sass files which caused the process to crash without processing any
      files. Issue #1827,

Deprecation – Must Read!

    * Support for Ruby 1.8.7 and 1.9.3 is deprecated. See this blog post for
      details.

    * The current handling of CSS variables is deprecated. In order to
      support the CSS spec as fully as possible, no Sass-specific constructs
      other than #{} will be supported in CSS variable values. For
      forwards-compatibility, any SassScript being used in CSS variables
      must be moved into #{}.