Logstash restart hangs during tests

[widhalmt]

Logstash in it's default configuration won't restart when there are messages in the pipeline that can't be written to an output.

There are two possible solution which should both work:

• Use persisted queues for Logstash. Make this optional but use it in every Molecule check just to be sure
• Set a parameter to allow unsafe restarts for Logstash

Personally I'd like to have both implemented.