test_launch_tor_with_config fails if a secondary tor process is running

Steps to reproduce -

1. start tor
2. start the stem integ tests

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                          test.integ.process                          
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test_launch_tor_with_config                                  [FAILURE]
test_launch_tor_with_timeout                                 [SUCCESS]

======================================================================
ERROR: test_launch_tor_with_config
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Traceback:
  File "/home/gsathya/stem/test/integ/process.py", line 35, in test_launch_tor_with_config
    completion_percent = 5
  File "/home/gsathya/stem/stem/process.py", line 171, in launch_tor_with_config
    return launch_tor(tor_cmd, None, torrc_path, completion_percent, init_msg_handler, timeout)
  File "/home/gsathya/stem/stem/process.py", line 119, in launch_tor
    raise OSError("Process terminated: %s" % last_problem)
OSError: Process terminated: No, it's still there.  Exiting.

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Ran 2 tests in 7.035s

FAILED