Test suite statistics

The test suite is still driving me crazy, so I'm dedicating some time to an investigation of it (them).

Links:

• https://www.foraker.com/blog/profiling-your-rspec-suite
• https://github.com/tmm1/stackprof
• http://www.rubyinside.com/careful-cutting-to-get-faster-rspec-runs-with-rails-5207.html
• http://engineering.freeagent.com/2016/05/05/four-hours-of-tests-in-four-minutes/

Let's see where the time is going.