Cap scss lint version

Fixes scss-lint to 0.25.1 until the task runner supports 0.26

![ ](http://gifs.joelglovier.com/oh-shit/tsunami.gif)
Just a note that there is no need for the caret here. Taken from the node sem ver docs:

> `^0.1.3` := `0.1.3` "Compatible with 0.1.3". `0.x.x` versions are special: since the semver spec specifies that 0.x.x versions make no stability guarantees, only the version specified is considered valid.