Version 0.84-pre

• Add support for read receipts on /receive - thanks @jneidel
• Add endpoint support for individual read receipts - thanks @brettp
• Improved README.md - thanks @jaanli and @vorwd
• updated signal-cli to v0.13.3
• added username support to /v2/send endpoint

This is a pre-release. If you want to give it a try, use the following docker image tag: bbernhard/signal-cli-rest-api:0.159-dev