Add karma config update reference to step 11 of the tutorial

Request Type: docs

How to reproduce: On step 11 of the tutorial if you just follow the instructions on the main page the unit tests will fail.

Component(s): 

Impact: small

Complexity: small

This issue is related to: 

**Detailed Description:**

When including the ng-resource module you appear to need to add a reference to the karma config file as well or the unit tests will fail. This burned me for a while when going through the tutorial.

**Other Comments:**