More fixes to make commercial X-browser

 * stop using `Array`'s some (use `lodash`'s)
 * don't use `bonzo`'s `css` method if `getComputedStyle` doesn't exist
Exactly, that's why [this technique](https://github.com/guardian/frontend/commit/7efef98a1ce436e67edc216f54ded6b00b1aa3d9) handle these cases without resorting to littering our code with browser-specific conditionals.
Unless anyone has a valid reason, reverting back to that