Update Kafka Client

The one [we use](https://github.com/brave-intl/bat-ledger/blob/master/package.json#L95) ([sinek](https://github.com/nodefluent/node-sinek)) had support dropped a year ago. Let's move to https://github.com/tulios/kafkajs
