Error when installing via bower

When I installed via bower, an exception was thrown saying that the slider controller's `ranges` property was undefined when trying to push the range into it in the slider range directive. Using Angular 1.4.8. I couldn't figure out why, because it seems fairly straightforward. But when I copy and pasted the code from dist/ on Github into my project, the error was no longer thrown. Just thought I'd let you know.

Also, it might be a good idea to wrap your code in a self-invoking anonymous function so that variables like `sliderDirective` aren't declared globally.