Remove spurious script tag.

The js/models/store.js file has not appeared in the text, and does not appear in the associated diff for this page:

https://github.com/emberjs/quickstart-code-sample/commit/60feb5f369c8eecd9df3f561fbd01595353ce803
Merge pull request #795 from callahad/patch-1

Remove spurious script tag.