title: Use fetch instead of ajax with redux-observable
body: <p>In <code>redux-observable</code> is it possible to use <a href="https://github.com/matthew-andrews/isomorphic-fetch" rel="noreferrer">isomporphic-fetch</a> instead of <a href="https://github.com/Reactive-Extensions/RxJS-DOM/blob/master/doc/operators/ajax.md" rel="noreferrer">Rx.DOM.ajax</a>?</p>