UIColor.Type does not have a member named materialRed

I'm getting the following error:

UIColor.Type does not have a member named materialRed

Pod is installed and I've imported NilColorKit at the top of my swift file. 

Code

```
import NilColorKit

var x = UIColor.materialRed()
```

Am I missing something inside my code that is preventing this from working? Thanks. 

Is the preferred method just copy the module into my project?
