Docker environment

[learningcljs]

In reference to #340

We could even add instructions on creating a docker environment

It would be nice to have the development environment developed in this tutorial series available through docker. Having both boot tdd as well as boot repl -c.

[learningcljs]

I have tried to create this docker development environment with #349.

What I was aiming for was the complete modern-cljs development environment with docker.

The pull request falls short as I do not know how to link or network two contianers where the first is running boot tdd and the second is running boot repl -c.

boot repl -c seems to be dependent on boot tdd.

[learningcljs]

So the missing part that is not included in the instructions is how to get a container linked or networked with the first container running boot tdd so that the second container can run boot repl -c.