Review use of Logging in Test Machine

[99-not-out]

It hides a lot of output in the logs (well, its not strictly hidden but its not "in your face" when there are errors). It also uses stack trace pretty formatting which may not work with the 1.10 errors - and also means control sequences appear in the logs making the errors harder to read.

[cddr]

Do you think https://github.com/FundingCircle/jackdaw/pull/144 addresses the most significant problem described here? I can follow up on the stack-trace logging thing but that's only a dev dependency anyway and might be a "good first issue" by itself.