removed matches polyfill. 

reverses https://github.com/Financial-Times/o-dom/pull/3

@triblondon 
This syntax has changed.  Until we migrate polyfill.io, use polyfill.webservices.ft.com/v1/polyfill.min.js?features=selectors.

Except there isn't a polyfill called selectors, in either the new or old polyfill service.