[Helper] Add static map support

[egeloen]

This PR fixes #201 and allow to render the map as a static one with the following:

use Ivory\GoogleMap\Helper\Builder\StaticMapHelperBuilder;
use Ivory\GoogleMap\Map;

$map = new Map();
// Configure your map...

$staticMapHelper = StaticMapHelperBuilder::create()->build();

echo '<img src="'.$staticMapHelper->render($map).'" />';