Configuration::setMetadataCacheImpl is deprecated since mongodb-odm 2.2

[rieschl]

Hey!

The method \Doctrine\ODM\MongoDB\Configuration::setMetadataCacheImpl was deprecated in monbodb-odm 2.2.
This package calls it in the ConfigurationFactory, though.

Are there plans to upgrade this package to avoid the deprecation warning? Should I have a look at it?
At first glance, the most simple fix would be wrapping the current cache implementation (CacheAdapter::wrap($cacheImpl)) and call setMetadataCache() instead of setMetadataCacheImpl(). Maybe checking if the cache returned by $container->get($configurationOptions->getMetadataCache()) is already a PSR-6 cache, to be forward compatible.

Thanks!

[driehle]

Closed by #280