ProducerSettings should default to acks=All

[felixkrull-neuland]

Kafka's producer defaults to acks=all (docs) but this library's ProducerSettings defaults to acks=1. In my opinion, this is an unexpected change in behaviour from Kafka's defaults which is not what I expect from a wrapper library.

Also, according to the Kafka docs, the Acks.MinusOne variant is unnecessary because it's equivalent to all.

[nomisRev]

Hey @felixkrull-neuland,

IMO it makes sense to default to the same default as Kafka. I'm going to add this in the next release, if you're interested in contributing this I'd be happy to accept and merge the PR ☺️

[kfh]

@nomisRev Isn't this solved by #189 ? 🤔