test_session_init.py file-bridge test is racy

[Dimitri John Ledkov]

When doing:
while ./test_pyupstart_session_init.py; do :; done

Eventually one may get.

======================================================================
FAIL: test_init_start_file_bridge (__main__.TestFileBridge)
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Traceback (most recent call last):
  File "./test_pyupstart_session_init.py", line 309, in test_init_start_file_bridge
    self.assertTrue(wait_for_file(delete_file_job_logfile))
AssertionError: False is not true

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Ran 5 tests in 5.578s

It seems racy, and it hit a timeout of 5 seconds? (usually this test file completes in under a second). Do we know what went wrong, or is this simply inotify limitations?