Not working on rails 4.2.1

First, it's not updated on [rubygems](https://rubygems.org/gems/rails-backbone) server so instead of this 

```
gem "rails-backbone"
```

you should use this

```
gem "rails-backbone", "1.1.2", git: "https://github.com/codebrew/backbone-rails.git"
```

Second, Example usage isn't work either.

Thanks.
