Dry run should also generate the `docker-compose.yml` file

[ferranbt]

Right now the --dry-run command stops right before the Docker runtime is called. Thus, the docker-compose file is not generated. But, most of the time, you might want to run dry run to check that file.

[canercidam]

Any thoughts on how we want to output the file? Write it somewhere? Or to the stdout?

[ferranbt]

To the output folder. Right now the --dry-run method just writes down everything until the point of the docker-compose execution.