RuntimeWarning with respect to line buffering using Python 3.8.

[Viech]

I'm getting the following warning using Python 3.8.3 and concurrencytest 0.1.2:

Traceback (most recent call last):
  File "./test.py", line 191, in <module>
    result   = testRunner.run(testSuite)
  File "/usr/lib/python3.8/unittest/runner.py", line 176, in run
    test(result)
  File "/usr/lib/python3.8/unittest/suite.py", line 84, in __call__
    return self.run(*args, **kwds)
  File "/usr/lib/python3.8/site-packages/testtools/testsuite.py", line 83, in run
    tests = self.make_tests(self)
  File "/usr/lib/python3.8/site-packages/concurrencytest.py", line 96, in do_fork
    stream = os.fdopen(c2pread, 'rb', 1)
  File "/usr/lib/python3.8/os.py", line 1023, in fdopen
    return io.open(fd, *args, **kwargs)
RuntimeWarning: line buffering (buffering=1) isn't supported in binary mode, the default buffer size will be used