Stop swallowing errors in test-machine

[cddr]

When working with the test-machine, it makes for a significantly better developer workflow when any exceptions that occur are bubbled back up to the main thread. Prior versions were catching errors and sometimes not even logging them (mea culpa!).

This PR adds tests with a few of the errors we've seen developers make and ensures that the resulting exception (including the full cause trace) is logged and the exception is bubbled back up to the main thread after all the resources used by the test are torn back down.

[codecov-io]

Codecov Report

Merging #144 into master will decrease coverage by 0.18%.
The diff coverage is 75.53%.

@@            Coverage Diff             @@
##           master     #144      +/-   ##
==========================================
- Coverage   81.04%   80.85%   -0.19%     
==========================================
  Files          39       39              
  Lines        2321     2351      +30     
  Branches      147      149       +2     
==========================================
+ Hits         1881     1901      +20     
- Misses        293      301       +8     
- Partials      147      149       +2

Impacted Files	Coverage Δ
src/jackdaw/test/journal.clj	77.19% <100%> (-0.4%)	⬇️
src/jackdaw/test/transports/rest_proxy.clj	82.72% <62.5%> (-1.52%)	⬇️
src/jackdaw/test/transports/mock.clj	84.48% <72.72%> (-5.32%)	⬇️
src/jackdaw/test.clj	77.77% <83.33%> (+4.56%)	⬆️
src/jackdaw/test/transports/kafka.clj	85.93% <86.95%> (+0.33%)	⬆️
src/jackdaw/serdes/edn.clj	88.46% <0%> (-3.85%)	⬇️
src/jackdaw/test/commands/base.clj	100% <0%> (ø)	⬆️
... and 1 more

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[cddr]

This change addresses another usability problem encountered in the wild. Test authors could confuse the middleware if they wrote a condition? function that returned a map containing a :result key. The original intention was that the return value might be of interest to the test author when making assertions about the results but clearly it is safer to include the result in it's own :info key to make sure it doesn't collide with what the middleware is expecting to see.