Reflow text of quote on story hero, renamed bg image into 'story-hero' component

See new text flow below - just the quotation on the story hero has changed:

![crossfit tonbridge gocardless customer stories gocardless](https://cloud.githubusercontent.com/assets/2903904/4574516/4c3b55fa-4f9d-11e4-86cd-94aa52169a8e.png)
![the uk s 1 for online direct debit gocardless](https://cloud.githubusercontent.com/assets/2903904/4574517/4d97ee9a-4f9d-11e4-9c16-83cc9683fd71.png)