Switch statsd config to zuul.conf

The automatic statsd configuration based on env variables has
proven cumbersome and counter-intuitive.  Move its configuration
into zuul.conf in preparation for other components emitting stats.

Change-Id: I3f6b5010d31c05e295f3d70925cac8460d334283
diff --git a/tests/base.py b/tests/base.py
index dacb1ef..b029f0b 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -20,7 +20,6 @@
 import datetime
 import gc
 import hashlib
-import importlib
 from io import StringIO
 import json
 import logging
@@ -48,7 +47,6 @@
 import kazoo.client
 import kazoo.exceptions
 import pymysql
-import statsd
 import testtools
 import testtools.content
 import testtools.content_type
@@ -2047,14 +2045,9 @@
         self.config.set('executor', 'state_dir', self.executor_state_root)
 
         self.statsd = FakeStatsd()
-        # note, use 127.0.0.1 rather than localhost to avoid getting ipv6
-        # see: https://github.com/jsocol/pystatsd/issues/61
-        os.environ['STATSD_HOST'] = '127.0.0.1'
-        os.environ['STATSD_PORT'] = str(self.statsd.port)
+        if self.config.has_section('statsd'):
+            self.config.set('statsd', 'port', str(self.statsd.port))
         self.statsd.start()
-        # the statsd client object is configured in the statsd module import
-        importlib.reload(statsd)
-        importlib.reload(zuul.scheduler)
 
         self.gearman_server = FakeGearmanServer(self.use_ssl)