Change logging in stress test

Stress tests is now using the default tempest logging in order to use
tempest.conf for configuration. Every action registers a logger for
their own (previously they reported always as "stresstest").

Cleanup function is adapted as well.

Implements: bp stress-tests

Change-Id: I571d4b1ad7ced62b5d5b3e7faf8fa1a7e5f9504e
diff --git a/etc/logging.conf.sample b/etc/logging.conf.sample
index 685dd36..3b468f1 100644
--- a/etc/logging.conf.sample
+++ b/etc/logging.conf.sample
@@ -1,5 +1,5 @@
 [loggers]
-keys=root,tempest
+keys=root,tempest,tempest_stress
 
 [handlers]
 keys=file,syslog,devel
@@ -16,6 +16,11 @@
 handlers=file
 qualname=tempest
 
+[logger_tempest_stress]
+level=INFO
+handlers=file,devel
+qualname=tempest.stress
+
 [handler_file]
 class=FileHandler
 level=DEBUG