Need test for the common patterns for Exim

[purbon]

Relates to #53

Providing basic log lines to create this patterns would be also necessary.

The reason I didn't get round to doing this is because the logs I'm pushing into ELK are quite difficult to redact without making them meaningless in the sense of pattern matching. They contain a lot of PI data, which (obviously) I'm not at liberty to publish.

I can see what I can do but it's really difficult to take the real-life logs and make them meaningful in terms of testing...

[purbon]

@greem makes complete sense!

might be crafting some example lines with random data? would that be possible?