README should mention this project's features

At first, I thought only "Riot APIs" were supported.

APIs

I was just checking the project's source code and was surprised to see that it supports

• LCU API (HTTP and WebSocket),
• Replay API (even though it can be considered part of the LCU API),
• in addition to Riot APIs (I mean calls to whatever.api.riotgames.com) like Match V5.

It would be helpful for people checking out this project to know that all those different APIs are supported.

Caching

Also, about caching, it seems like you support (completely, partially, or planned) the following cache options (impls):

• Using multiple caches: TieredCacheProvider is a wrapper around other providers that propagates (or pipes) operations.

• No-op EmptyCacheProvider

• FileSystem: FileSystemCacheProvider

• In-memory: MemoryCacheProvider

• MongoDB: MongoDBCacheProvider via Morphia

• MyQSL: MySQLCacheProvider

Requirements

It looks like the only "newish" API you are using is the Time API, which was added in Java 8.
So, I assume a minimum version of Java 8 is required.