should wrapper-small be renamed?

[Adam Willoughby-Knox]

I thought wrapper-small should be replaced with wrapper wrapper--small

even the inline docs hint at this
<div class="wrapper {{modifier_class}}">Wrapper</div>

[Callum Strong]

This is something I did in my personal fork so I've created a pull request (#28). It also saves a couple of lines of code (every little helps).

[Tyler Childs]

I had it like that originally, which is why the docs allude to it, but had changed it. Merged in this PR, thanks @csscallum :)

Just getting back from a vacation, so I'll be more active again.