CI: Makefile/Docker testing

To test the build on various distro, I'm using docker containers and a Makefile for orchestration.

pros:

You are independent of third party CI runner config (e.g. github actions runners or Travis-CI VM images).
You can run it locally on your linux system.
Most CI provide runner with docker and Makefile installed (e.g. tarvis-ci minimal images.

cons:

Only GNU/Linux distro supported.
Could take few GiB (~30 GiB for all distro and all languages)
- ~500MiB OS + C++/CMake tools,
- ~150 MiB Python,
- ~400 MiB dotnet-sdk,
- ~400 MiB java-jdk.

Usage

To get the help simply type:

make

note: you can also use from top directory

make --directory=makefiles

For example to test Python inside an Alpine container:

make alpine_python_test

Dockerfile is split in several stages.