Distinguish betwen messages leaving and entering the cluster

Implemented an additional message attribute called direction, which allows distinguishing between messages leaving and entering the cluster

Config file

Read RabbitMQ and Elasticsearch configuration parameters from file instead of CLI arguments (by default, /etc/rmqfwd.toml). This should improve usability and is a first step towards packaging the program executable along-side a default configuration file and a systemd unit.

Also, a significant amount of boilerplate has been removed from the main.rs module, where possible using the Result type instead of resorting to expect and unwrap calls

Flatter messages

• Leverage serde's flexible serialisation options to persist Rabbit messages in a flat, query-friendly structure. This should play nicely with Kibana, while also simplifying the underlying queries in Elasticsearch.
• Scrap a good amount of boiler plate by introducing structopt, a nice library that maps cli subcommands and options into Rust types.

rmqfwd v0.2.0

Implement a new id flag for the export and the replay sub-commands. This allows operating directly on messages stored in the document store as opposite of select them through a query

Basic trace, export and republish functionality

v0.0.1

increase timeout for init script