Counter example for listenable browser

This repo is basically a clone of redux counter example. The only modification I made is I added following code in ./components/Counter.js's render method:

say(`Counter value is ${value}`).then(() => listenForUserInput({
    'increment': onIncrement,
    'increment if odd': this.incrementIfOdd,
    'increment asynchronously': this.incrementAsync,
    'decrement': onDecrement
}))

I also added a polyfill for other than listenable browsers:

<script src="https://hermanya.github.io/listenable-browser/support_for_other_browsers.js"></script>