Log Message:
Changes 13.1.0:
- trial now has an --exitfirst flag which stops the test run after
  the first error or failure.
- twisted.internet.ssl.CertificateOptions now supports chain
  certificates.
- twisted.internet.endpoints now provides ProcessEndpoint, a child
  process endpoint.
- Factory now has a forProtocol classmethod that constructs an
  instance and sets its protocol attribute.
- twisted.internet.endpoints.connectProtocol allows connecting to a
  client endpoint using only a protocol instance, rather than
  requiring a factory.
- twisted.trial.unittest.SynchronousTestCase.assertNoResult no longer
  swallows the result, if the assertion succeeds.
- twisted.python.constants.FlagConstant implements __iter__ so that
  it can be iterated upon to find the flags that went into a flag
  set, and implements __nonzero__ to test as false when empty.
- assertIs and assertIsNot have now been added to
  twisted.trial.unittest.TestCase.
- twisted.trial.unittest.TestCase.failureResultOf now takes an
  optional expected failure type argument.
- The POSIX implementation of
  twisted.internet.interfaces.IReactorProcess now does not change the
  parent process UID or GID in order to run child processes with a
  different UID or GID.