Update pytest log handling

In pytest 3.4, we now need to explicitly set the log level and caplog.at_level
now sets the level of the root handler.

pytest.ini

@@ -1,4 +1,5 @@
 [pytest]
+log_level = NOTSET
 addopts = --strict -rfEw --faulthandler-timeout=90 --instafail --pythonwarnings error --benchmark-columns=Min,Max,Median
 testpaths = tests
 markers =

tests/helpers/logfail.py

@@ -22,7 +22,6 @@
 import logging
 
 import pytest
-import _pytest.logging
 
 
 class LogFailHandler(logging.Handler):
@@ -40,17 +39,8 @@ class LogFailHandler(logging.Handler):
         if logger.name == 'messagemock':
             return
 
-        for h in root_logger.handlers:
-            if isinstance(h, _pytest.logging.LogCaptureHandler):
-                capture_handler = h
-                break
-        else:
-            # The LogCaptureHandler is not available anymore during fixture
-            # teardown, so we ignore logging messages emitted there..
-            return
-
         if (logger.level == record.levelno or
-                capture_handler.level == record.levelno):
+                root_logger.level == record.levelno):
             # caplog.at_level(...) was used with the level of this message,
             # i.e.  it was expected.
             return