Add documentation on how to test using docker

[leophys]

I am currently using with proficency docker to both start an instance of libreant and to pull and use different elasticsearch versions from here (FANTASTIC!).

I do the following to build a docker image for libreant, using the Dockerfile present right now in dev

(in the root of the project)

# docker build -t libreant . --build-arg=ES_VERSION=<es_version>

and to run

# docker run --rm -t libreant

I pull different versions of elasticsearch from the above repository with

# docker pull docker.elastic.co/elasticsearch/elasticsearch:<es_version>

Then I run it, binding ports 9200 and 9300 to localhost with

# docker run --rm -p 127.0.0.1:9200:9200 -p 127.0.0.1:9300:9300 -t docker.elastic.co/elasticsearch/elasticsearch:<es_version>

Shall I document it?

[leophys]

I realized that my understanding of docker at the time was crap.

I made a modern-docker branch in my fork to use docker-compose. I'd divert this issue to one of general enhancement of the development process.

[boyska]

I made a `moder-docker` branch in my fork to use docker-compose. I'd divert this issue to one of general enhancement of the development process.

cool! I think that libreant has other problems, compared to this :) (I mean: noone is actively developing it, so modernizing the development environment is not a priority for me). But of course feel free, looks much better now! if you are seriously into re-taking it and fixing some old bugs, I think I can give you some help