add a Dockerfile

[zoobab]

add a Dockerfile

[Pryz]

Hey @zoobab,

Thanks for you PR. How do you plan to use this Dockerfile ?

I would prefer having the "build" part in the Makefile and just use a minimal OS for the Docker image. Like a FROM scratch or something. But all depend on how you are planning to use this Dockerfile :)

[zoobab]

The goal is to have a way to build a release in a pretty reproductible way.

Right now, I am building a binary for Linux, tell me if I need to add some steps to cross-compile binaries for other platforms.

Github has a crappy way to make a binary releases (upload a file from the dev laptop). So at least if 2 people can run the same ./build.sh and obtain the same md5sum of the output binaries, I am already happy.

[zoobab]

Tell me if I need to cross-compile for other platforms (darwin_amd64, windows_amd64), or even ARM...