CLI command env outputs success message in case of an error

[bossenti]

Body

When using the CLI installer's command streampipes env --set xy the cli returns a success log message even if some error occurred and the command is not executed successfully.
For example:

./streampipes env --set ui
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
[INFO] Set environment to 'ui'

In case of an error, the command should exit and create a proper console output.
This might also effect other commands of the cli installer.

Mentoring

As this ticket is marked as good first issue: @dominikriemer, @tenthe or @bossenti are happy to provide help for getting started, just tag (one of) them if you want to start working on this issue and need some help.
This issue might be a good issue for people who are interested in StreamPipes and have some experience with bash scripts.

StreamPipes Committer

I acknowledge that I am a maintainer/committer of the Apache StreamPipes project.