Better handle interrupts

[Bo98]

Currently if you hit Ctrl+C, the underlying rspec tests might continue to still run. This behaviours seemed to consistently happen in my environment (executed via bundle exec).

This PR adopts logic similar to parallel_tests that fixes this: https://github.com/grosser/parallel_tests/blob/6e9be6f529b64e5f9c8e4439754bca0b2ef3f2b1/lib/parallel_tests/cli.rb#L31-L54

An extra consideration for turbo_tests was that the Ctrl+C might happen before the FIFO file was written to, causing the read thread to block indefinitely. A fix for this is to make the process exit monitoring thread write to the FIFO file (if not already written to) to signal the other thread to stop.

[ilyazub]

@Bo98 Thanks for your work and my apologies for not reviewing your PRs sooner.

Let's also handle the race condition in handle_interrupt when the PID file was removed.

[ilyazub]

Let's also handle race condition when the PID file was removed.

$ bundle exec turbo_tests
Using recorded test runtime
3 processes for 3 specs, ~ 1 specs per process

Randomized with seed 27875

......

Finished in 3.36 seconds (files took 3.12 seconds to load)
6 examples, 0 failures


Randomized with seed 27875

#<Thread:0x0000000001b5c2b8 $HOME/Workspace/turbo_tests/lib/turbo_tests/runner.rb:224 run> terminated with exception (report_on_exception is true):
Traceback (most recent call last):
	1: from $HOME/Workspace/turbo_tests/lib/turbo_tests/runner.rb:232:in `block in start_subprocess'
$HOME/Workspace/turbo_tests/lib/turbo_tests/runner.rb:232:in `write': No such file or directory @ rb_sysopen - tmp/test-pipes/subprocess-2 (Errno::ENOENT)
bundler: failed to load command: turbo_tests ($HOME/.rbenv/versions/2.7.2/lib/ruby/gems/2.7.0/bin/turbo_tests)
Traceback (most recent call last):
	1: from $HOME/Workspace/turbo_tests/lib/turbo_tests/runner.rb:232:in `block in start_subprocess'
$HOME/Workspace/turbo_tests/lib/turbo_tests/runner.rb:232:in `write': No such file or directory @ rb_sysopen - tmp/test-pipes/subprocess-2 (Errno::ENOENT)

Suggested change

	rescue Errno::ESRCH
	rescue Errno::ESRCH, Errno::ENOENT