Bump dependencies and Pkl CLI version 🚀 (#10)

Ready for production 🎉

Remove `symfony/serializer` and `symfony/property-access` dependencies (

#8)

Remove `symfony/http-client` dependency (#7)

Fix `ttl` parsing for APCu and Memcached adapters

Rename `Cache` to `CacheAdapter` (#6)

Add Memcached cache backend (#5)

Better caching with automatic refresh on stalled entry + renamed cach…

…e command to `warmup` (#3)

* Automatic cache miss addition and refresh of staled cache

* Renamed `dump` command to `warmup` and invalidate cache if it is unreadable

`Cache` becomes `PersistentCache`, a PSR-16 compliant cache system (#2)

Update `Phikl` namespace