spread-mir-ci

Spread is a plesant way distribute full-system integration tests and
similar tasks. A few simple and concrete concepts that are fun to play
with and fix the exact piece missing in the puzzle. It's not Jenkins,
it's not Travis, it's not a library, not a language, and it's not even
specific to testing. It's a simple way to express what to run and
where, what to do before and after it runs, and how to duplicate jobs
with minor variations without copy & paste.