MYLOC-12 added geolocation module with tests

Here's a simple abstraction around the browser Geolocation API.
We should use the same options as locator_news_responsive. See https://github.com/BBC-Location-Services/locator_news_responsive_js/blob/master/src/js/locator/locatorView.js

```
{
    enableHighAccuracy : true,
    maximumAge: 60,
    timeout: 1000
}
```