As jQuery 1.7.2 is the lowest version of jQuery supported by Select2,
it makes sense to run the tests on it. For the most part, we can
assume that the newer versions of Select2 are backwards compatible
enough such that this isn't an issue.
The recommended version of jQuery to use is the latest though, which
is why the jQuery file is only included in the tests.
This revealed a few issues with our data fallbacks and `.append`
functionality that was introduced in jQuery 1.8.
