Update jasmine to 2.0.2

Also cleaned up the jasmine environment. Jasmine 2
uses poltergeist instead of selenium-webdriver and
so is jenkins-friendly. Additionally, it's now 
possible to use the asset pipeline to include source
assets instead of having to maintain a list in jasmine.yml.

Tests do not pass (and didn't before this change).
Added jquery to jasmine manifest
Stop Jasmine auto-installing phantom js
Merge pull request #409 from alphagov/headless-js-ci

Update jasmine to 2.0.2