a simpler design for EventStore

>> we would have to create hacks to have this work with our normal database schema generation

I would say that that is a shortcoming of the existing tooling. But I guess it doesn't hurt here. 

I specifically don't want generic DbalPersistence or DoctrinePersistence, because I want to leave open the possibility of having specific drivers that are optimised for specific databases. DBAL is a generic solution by nature. 

As for testing, there already is an InMemory driver which doesn't require sqlite.