tests: Rewrites some tests in test_errorhandling for simplification
tests: Rewrites some tests in test_errorhandling for simplification

This patch adds a Fixture for all tests in test_errorhandling
that ensures logs stay synchronous during the execution of the
tests in its test case.

Change-Id: Ia6805cd5c3d1df7a7dead4585d1a6b6c595b88ee
Reviewed-on: http://gerrit.aldebaran.lan/86464
Reviewed-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@external.softbankrobotics.com>
Tested-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@external.softbankrobotics.com>
Reviewed-by: jlamotte <70353e7b0c7d18b7fc75605daf0ccba69fcd3222@aldebaran.com>
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi