Have all unit tests import from our own subclass of trial's unittest TestCase; set up logging in ONE PLACE ONLY

tests/federation/test_federation.py

@@ -14,11 +14,10 @@
 
 # trial imports
 from twisted.internet import defer
-from twisted.trial import unittest
+from tests import unittest
 
 # python imports
 from mock import Mock
-import logging
 
 from ..utils import MockHttpResource, MockClock
 
@@ -28,9 +27,6 @@ from synapse.federation.units import Pdu
 from synapse.storage.pdu import PduTuple, PduEntry
 
 
-logging.getLogger().addHandler(logging.NullHandler())
-
-
 def make_pdu(prev_pdus=[], **kwargs):
     """Provide some default fields for making a PduTuple."""
     pdu_fields = {