Show functional test request logging

* Failed test cases will show all captured logging
* Forward OS_*_CAPTURE environment variables along from tox to testr

Change-Id: Ice9a64d07bb77dd46fb1da6a8ffaa8fd85d5f38b

functionaltests/__init__.py

@@ -0,0 +1,7 @@
+import logging
+
+logging.basicConfig(
+    filename='functional-tests.log',
+    filemode='w',
+    level=logging.DEBUG,
+)

tox.ini

@@ -67,6 +67,10 @@ usedevelop = False
 setenv = VIRTUAL_ENV={envdir}
          OS_TEST_PATH=functionaltests/
 passenv = TEMPEST_CONFIG
+          OS_STDOUT_CAPTURE
+          OS_STDERR_CAPTURE
+          OS_LOG_CAPTURE
+          OS_DEBUG
 
 [testenv:venv]
 commands = {posargs}