Changes this to use just communicate(), not the subprocess.PIPE stuff (which
apparently can do Weird Things)
Also rename the install variable to cmd in the install function
This eases the CPU and thread requirements of our tests (by forking
less, not doing everything at once). It should also speed up the tests
by avoiding certain repetitive work.
Updates https://github.com/letsencrypt/letsencrypt/issues/712
Run builds in parallell as well as starting servers in parallel.
Wait for the servers to come up, so tests don't start running too early.
Enable race detection only for the integration test, not for start.py.
Previously I'd suggested it should always be on, but after running with it for a
while I'm convinced it's too slow for start.py (but still very valuable for
integration tests!).
Jacob Hoffman-Andrews
Jeff Hodges
Tom Clegg