* DEV: Add a new way to run specs in parallel with better output
This commit:
1. adds a new executable, `bin/interleaved_rspec` which works much like
`rspec`, but runs the tests in parallel.
2. adds a rake task, `rake interleaved:spec` which runs the whole test
suite.
3. makes autospec use this new wrapper by default. You can disable this
by running `PARALLEL_SPEC=0 rake autospec`.
It works much like the `parallel_tests` gem (and relies on it), but
makes each subprocess use a machine-readable formatter and parses this
output in order to provide a better overall summary.
(It's called interleaved, because parallel was taken and naming is
hard).
* Make popen3 invocation safer
* Use FileUtils instead of shelling out
* DRY up reporter
* Moved summary logic into Reporter
* s/interleaved/turbo/g
* Move Reporter into its own file
* Moved run into its own class
* Moved Runner into its own file
* Move JsonRowsFormatter under TurboTests
* Join on threads at the end
* Acted on feedback from eviltrout
