Add Jasmine syntax 

Hi! 

I've added the Jasmine syntax to the package (inheriting from the base JS). Here is a from/to to see how it looks:

**From**
![from](https://cloud.githubusercontent.com/assets/692077/3142691/aa001db8-e9ce-11e3-9596-aa45a97b1364.png)

**To**
![to](https://cloud.githubusercontent.com/assets/692077/3142692/b4fcb776-e9ce-11e3-91c4-a6ff71517cea.png)


If you're not convinced with the color on the `describe` and `it` methods, let me know. I didn't highlight the other common functions like `beforeEach` because I think it becomes unreadable.