Link broken on ContactManager project page

On the [ContactManager](https://github.com/JumpstartLab/curriculum/blob/master/source/projects/contact_manager.markdown) project page, the link [general Ruby setup](http://jumpstartlab.com/resources/general/environment/) leads to file not found error.

I guess it should link [here](http://tutorials.jumpstartlab.com/topics/environment/environment.html).