testing tutorials

[edublancas]

Soopervisor requires many dependencies installed for users to try it. For that reason, our example includes a Dockerfile so people can try them out quickly. However, this tutorials (example) are not tested and often break; what is worst, they remain unnoticed until someone tries them and reports a problem (#91). So we should find a way to test them.

While we could add command on github actions to test the docker run commands; they might become outdated if we update the tutorials but do not test the github actions script. So I think it's best to write a script that extracts those commands and then runs them.

I actually started doing some of this work but never finished it; however, it already has the right pieces.

I'm unsure how much of a priority this, so I'll leave it to @idomic to decide when we start working on this.

cc @94rain