Workaround for a known bug in gulp-sass.

gulp-sass will not compile .sass files without this option enabled. See [https://github.com/dlmanning/gulp-sass/issues/55#issuecomment-47708591]

Reproduce;
* Create a new .sass file with a simple test;
~~~
div
  margin: 10px
~~~
* Add it to your gulpfile and run `gulp`.

It will error out with `Error: stdin:1: invalid top-level expression`

This fix adds some nasty comments, but the compilation works.