Code review comment for ~binli/checkbox-support/+git/checkbox-support:dmic-support

@Sylvain,

 Thanks for your feedback. And I try to run 'setup.py test' in the master branch, it also failed in several testcases. I just pasted part of result.

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FAIL: test_SPDIF_in_port_label (checkbox_support.parsers.tests.test_pactl.AttributeTests)
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Traceback (most recent call last):
  File "/work/source/gits/checkbox-dev/checkbox-support/checkbox_support/parsers/tests/test_pactl.py", line 522, in test_SPDIF_in_port_label
    self.assertEqual(attr.value[0].latency_offset, 0)
AssertionError: ([0], {}) != 0

====================================================================== FAIL: test_many_ports (checkbox_support.parsers.tests.test_pactl.AttributeTests)
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Traceback (most recent call last):
  File "/work/source/gits/checkbox-dev/checkbox-support/checkbox_support/parsers/tests/test_pactl.py", line 443, in test_many_ports
    self.assertEqual(attr.value[0].availability, '')
AssertionError: ([''], {}) != ''

======================================================================
FAIL: test_one_port (checkbox_support.parsers.tests.test_pactl.AttributeTests)
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Traceback (most recent call last):
  File "/work/source/gits/checkbox-dev/checkbox-support/checkbox_support/parsers/tests/test_pactl.py", line 421, in test_one_port
    self.assertEqual(attr.value[0].availability, 'available')
AssertionError: (['available'], {}) != 'available'