Logstash tests

[widhalmt]

We need to check whether Logstash can work with the certificates we create.

[widhalmt]

I found two problems in a local testenvironment:

• The PKCS8 is not to be found on the system, even when the corresponding task was shown as changed
• The PCS8 key is generated with a passphrase. And as far as I know, Logstash beats input breaks when there's a passphrase on the key. Nevertheless, our default configuration doesn't include a passphrase in the beats input so it can't work anyway.